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Can you take Diphenhydramine with Pentazocine?

1 drug interaction and 47 additional warnings found for the following 2 drugs:

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Drug interactions

Moderate drug interactions

Moderate:

diphenhydrAMINE pentazocine

Applies to: diphenhydramine and pentazocine

Using diphenhydrAMINE together with pentazocine may increase side effects such as:

  • dizziness
  • drowsiness
  • confusion
  • difficulty concentrating

Some people, especially the elderly, may also experience impairment in thinking, judgment, and motor coordination.

What to do: You should avoid or limit the use of alcohol while being treated with these medications. Also avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medications affect you.

Talk to your doctor if you have any questions or concerns. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Food/lifestyle interactions

Major food/lifestyle interactions

Major:

pentazocine Food/Lifestyle

Applies to: pentazocine

Do not use alcohol or medications that contain alcohol while you are receiving treatment with pentazocine. This may increase nervous system side effects such as:

  • drowsiness
  • dizziness
  • lightheadedness
  • difficulty concentrating
  • impairment in thinking and judgment

In severe cases, low blood pressure, respiratory distress, fainting, coma, or even death may occur.

Do not use more than the recommended dose of pentazocine, and avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medication affects you.

Smoking tobacco may also reduce the blood levels and effects of pentazocine. Contact your doctor if pentazocine is not adequately controlling your symptoms.

It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medication without first talking to your doctor.

Major:

pentazocine Alcohol (Ethanol)

Applies to: pentazocine

Do not use ethanol (alcohol) while you are receiving treatment with pentazocine.

This may increase nervous system side effects such as:

  • drowsiness
  • dizziness
  • lightheadedness
  • difficulty concentrating
  • impairment in thinking and judgment

In severe cases, low blood pressure, respiratory distress, fainting, coma, or even death may occur.

Talk to your doctor or pharmacist if you have questions on how to take this or other medications you are prescribed.

Do not use more than the recommended dose of pentazocine and avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medication affects you.

It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medication without first talking to your doctor.

Moderate food/lifestyle interactions

Moderate:

diphenhydrAMINE Alcohol (Ethanol)

Applies to: diphenhydramine

Ask your doctor before using diphenhydrAMINE together with ethanol (alcohol).

Use alcohol cautiously. Alcohol may increase drowsiness and dizziness while you are taking diphenhydrAMINE.

You should be warned not to exceed recommended dosages and to avoid activities requiring mental alertness.

If your doctor prescribes these medications together, you may need a dose adjustment to safely take this combination.

It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Disease interactions

44 potential interactions Applies to: 32 conditions, including Depression, Constipation, Asthma, COPD, and Seizures.

Acute Alcohol Intoxication

Major:

pentazocine

Pentazocine has a major potential interaction with Acute Alcohol Intoxication.

Opioid partial agonists may produce respiratory depression by decreasing respiratory drive and increasing airway resistance. A "ceiling effect" has been noted for these agents and increasing doses do not produce proportional or further respiratory depression. However, the duration of effect is prolonged. At therapeutic analgesic dosages, the respiratory effects are usually not clinically important except in patients with preexisting pulmonary impairment. Therapy with opioid partial agonists should be avoided or administered with extreme caution and initiated at reduced dosages in patients with severe CNS or respiratory depression; acute alcohol intoxication; sleep apnea; hypoxia, anoxia, or hypercapnia; upper airway obstruction; chronic pulmonary insufficiency; a limited ventilatory reserve; or other respiratory disorders. In the presence of excessive respiratory secretions, the use of opioid partial agonists may also be problematic because they decrease ciliary activity and reduce the cough reflex. Caution is also advised in patients who may be at increased risk for respiratory depression, such as comatose patients or those with head injury, intracranial lesions, or intracranial hypertension. Clinical monitoring of pulmonary function is recommended, and equipment for resuscitation should be immediately available if parenteral routes are used. Naloxone may be administered to reverse clinically significant respiratory depression.

Adrenal Insufficiency

Moderate:

pentazocine

Pentazocine has a moderate potential interaction with Adrenal Insufficiency.

Patients with Addison's disease may have increased risk of respiratory depression and prolonged CNS depression associated with the use of narcotic (opioid) analgesic agents. Conversely, these agents may cause or potentiate adrenal insufficiency. Therapy with opioids should be administered cautiously and initiated at reduced dosages in patients with adrenocortical insufficiency. Subsequent doses should be titrated based on individual response rather than a fixed dosing schedule.

Alcoholism

Major:

pentazocine

Pentazocine has a major potential interaction with Alcoholism.

Opioid partial agonists have the potential to cause dependence and abuse, particularly in patients with a history of drug abuse. Tolerance as well as physical and psychological dependence can develop after prolonged use, and abrupt cessation or a significant reduction in dosage may precipitate withdrawal symptoms. Because of their opioid antagonistic effect, withdrawal symptoms may also occur if opioid partial agonists are administered to patients with an opioid dependence or in whom substantial amounts of narcotics have recently been administered. Therapy with opioid partial agonists is not recommended in patients who are physically dependent on narcotics. Addiction-prone individuals, such as those with a history of alcohol or substance abuse, should be under careful surveillance or medical supervision when treated with opioid partial agonists. It may be prudent to refrain from dispensing large quantities of medication to these patients. After prolonged use or if dependency is suspected, withdrawal of opioid therapy should be undertaken gradually using a dosage-tapering schedule.

Altered Consciousness

Major:

pentazocine

Pentazocine has a major potential interaction with Altered Consciousness.

Opioid partial agonists may produce respiratory depression by decreasing respiratory drive and increasing airway resistance. A "ceiling effect" has been noted for these agents and increasing doses do not produce proportional or further respiratory depression. However, the duration of effect is prolonged. At therapeutic analgesic dosages, the respiratory effects are usually not clinically important except in patients with preexisting pulmonary impairment. Therapy with opioid partial agonists should be avoided or administered with extreme caution and initiated at reduced dosages in patients with severe CNS or respiratory depression; acute alcohol intoxication; sleep apnea; hypoxia, anoxia, or hypercapnia; upper airway obstruction; chronic pulmonary insufficiency; a limited ventilatory reserve; or other respiratory disorders. In the presence of excessive respiratory secretions, the use of opioid partial agonists may also be problematic because they decrease ciliary activity and reduce the cough reflex. Caution is also advised in patients who may be at increased risk for respiratory depression, such as comatose patients or those with head injury, intracranial lesions, or intracranial hypertension. Clinical monitoring of pulmonary function is recommended, and equipment for resuscitation should be immediately available if parenteral routes are used. Naloxone may be administered to reverse clinically significant respiratory depression.

Asphyxia

Major:

pentazocine

Pentazocine has a major potential interaction with Asphyxia.

Opioid partial agonists may produce respiratory depression by decreasing respiratory drive and increasing airway resistance. A "ceiling effect" has been noted for these agents and increasing doses do not produce proportional or further respiratory depression. However, the duration of effect is prolonged. At therapeutic analgesic dosages, the respiratory effects are usually not clinically important except in patients with preexisting pulmonary impairment. Therapy with opioid partial agonists should be avoided or administered with extreme caution and initiated at reduced dosages in patients with severe CNS or respiratory depression; acute alcohol intoxication; sleep apnea; hypoxia, anoxia, or hypercapnia; upper airway obstruction; chronic pulmonary insufficiency; a limited ventilatory reserve; or other respiratory disorders. In the presence of excessive respiratory secretions, the use of opioid partial agonists may also be problematic because they decrease ciliary activity and reduce the cough reflex. Caution is also advised in patients who may be at increased risk for respiratory depression, such as comatose patients or those with head injury, intracranial lesions, or intracranial hypertension. Clinical monitoring of pulmonary function is recommended, and equipment for resuscitation should be immediately available if parenteral routes are used. Naloxone may be administered to reverse clinically significant respiratory depression.

Asthma

Moderate:

diphenhydramine

diphenhydrAMINE has a moderate potential interaction with Asthma.

Oral anxiolytic, sedative, and hypnotic agents may cause respiratory depression and apnea when given in high dosages or following acute overdose. However, some patients may be susceptible at commonly used dosages, including the elderly, debilitated or severely ill patients, those receiving other CNS depressants, and those with limited ventilatory reserve, chronic pulmonary insufficiency or other respiratory disorders. Therapy with anxiolytic, sedative, and hypnotic agents should be administered cautiously in these patients. Appropriate monitoring and individualization of dosage are recommended.

Moderate:

diphenhydramine

diphenhydrAMINE has a moderate potential interaction with Asthma.

It has been suggested that the anticholinergic effect of antihistamines may reduce the volume and cause thickening of bronchial secretions, resulting in obstruction of respiratory tract. Some manufacturers and clinicians recommend that therapy with antihistamines be administered cautiously in patients with asthma or chronic obstructive pulmonary disease.

Biliary Obstruction

Moderate:

pentazocine

Pentazocine has a moderate potential interaction with Biliary Obstruction.

Opioid agonists may cause spasm of the sphincter of Oddi, which may increase biliary tract pressure. Other opioid-induced effects may include a reduction in biliary and pancreatic secretions and transient elevations in serum amylase. Patients with biliary tract disease (including acute pancreatitis) should be regularly evaluated for worsening symptoms. Therapy with opioids should be administered cautiously in patients with biliary tract disease, gallbladder disease, or acute pancreatitis.

Brain Tumor

Major:

pentazocine

Pentazocine has a major potential interaction with Brain Tumor.

The hypoventilation associated with administration of opioid partial agonists can induce cerebral hypoxia and vasodilatation with resultant increase in intracranial pressure. Unless mechanical ventilation is provided, extreme caution is advised when opioid partial agonists are given to patients with head injury, intracranial lesions, or a preexisting elevated CSF pressure. Also, clinicians treating such patients should be aware that opioid partial agonists may interfere with the evaluation of CNS function, especially with respect to consciousness levels, respiratory status, and pupillary changes.

Major:

pentazocine

Pentazocine has a major potential interaction with Brain Tumor.

Opioid partial agonists may produce respiratory depression by decreasing respiratory drive and increasing airway resistance. A "ceiling effect" has been noted for these agents and increasing doses do not produce proportional or further respiratory depression. However, the duration of effect is prolonged. At therapeutic analgesic dosages, the respiratory effects are usually not clinically important except in patients with preexisting pulmonary impairment. Therapy with opioid partial agonists should be avoided or administered with extreme caution and initiated at reduced dosages in patients with severe CNS or respiratory depression; acute alcohol intoxication; sleep apnea; hypoxia, anoxia, or hypercapnia; upper airway obstruction; chronic pulmonary insufficiency; a limited ventilatory reserve; or other respiratory disorders. In the presence of excessive respiratory secretions, the use of opioid partial agonists may also be problematic because they decrease ciliary activity and reduce the cough reflex. Caution is also advised in patients who may be at increased risk for respiratory depression, such as comatose patients or those with head injury, intracranial lesions, or intracranial hypertension. Clinical monitoring of pulmonary function is recommended, and equipment for resuscitation should be immediately available if parenteral routes are used. Naloxone may be administered to reverse clinically significant respiratory depression.

Cardiovascular Conditions and Disorders

Moderate:

diphenhydramine

diphenhydrAMINE has a moderate potential interaction with Cardiovascular Conditions and Disorders.

Antihistamines may infrequently cause cardiovascular adverse effects related to their anticholinergic and local anesthetic (quinidine-like) activities. Tachycardia, palpitation, ECG changes, arrhythmias, hypotension, and hypertension have been reported. Although these effects are uncommon and usually limited to overdosage situations, the manufacturers and some clinicians recommend that therapy with antihistamines be administered cautiously in patients with cardiovascular disease, hypertension, and/or hyperthyroidism.

Cerebral Vascular Disorder

Major:

pentazocine

Pentazocine has a major potential interaction with Cerebral Vascular Disorder.

Opioid partial agonists may produce respiratory depression by decreasing respiratory drive and increasing airway resistance. A "ceiling effect" has been noted for these agents and increasing doses do not produce proportional or further respiratory depression. However, the duration of effect is prolonged. At therapeutic analgesic dosages, the respiratory effects are usually not clinically important except in patients with preexisting pulmonary impairment. Therapy with opioid partial agonists should be avoided or administered with extreme caution and initiated at reduced dosages in patients with severe CNS or respiratory depression; acute alcohol intoxication; sleep apnea; hypoxia, anoxia, or hypercapnia; upper airway obstruction; chronic pulmonary insufficiency; a limited ventilatory reserve; or other respiratory disorders. In the presence of excessive respiratory secretions, the use of opioid partial agonists may also be problematic because they decrease ciliary activity and reduce the cough reflex. Caution is also advised in patients who may be at increased risk for respiratory depression, such as comatose patients or those with head injury, intracranial lesions, or intracranial hypertension. Clinical monitoring of pulmonary function is recommended, and equipment for resuscitation should be immediately available if parenteral routes are used. Naloxone may be administered to reverse clinically significant respiratory depression.

Major:

pentazocine

Pentazocine has a major potential interaction with Cerebral Vascular Disorder.

The hypoventilation associated with administration of opioid partial agonists can induce cerebral hypoxia and vasodilatation with resultant increase in intracranial pressure. Unless mechanical ventilation is provided, extreme caution is advised when opioid partial agonists are given to patients with head injury, intracranial lesions, or a preexisting elevated CSF pressure. Also, clinicians treating such patients should be aware that opioid partial agonists may interfere with the evaluation of CNS function, especially with respect to consciousness levels, respiratory status, and pupillary changes.

Constipation

Major:

pentazocine

Pentazocine has a major potential interaction with Constipation.

Narcotic (opioid) analgesic agents increase smooth muscle tone in the gastrointestinal tract and decrease peristalsis, which can lead to elevated intraluminal pressure, spasm, and constipation following prolonged use. In patients with severe or acute inflammatory bowel disease, the decrease in colonic motility may induce toxic megacolon. Therapy with opioids should be administered cautiously in patients with gastrointestinal obstruction, constipation, inflammatory bowel disease, or recent gastrointestinal tract surgery. Gastrointestinal effects appear to be the most pronounced with morphine.

COPD

Moderate:

diphenhydramine

diphenhydrAMINE has a moderate potential interaction with COPD.

It has been suggested that the anticholinergic effect of antihistamines may reduce the volume and cause thickening of bronchial secretions, resulting in obstruction of respiratory tract. Some manufacturers and clinicians recommend that therapy with antihistamines be administered cautiously in patients with asthma or chronic obstructive pulmonary disease.

Depression

Major:

diphenhydramine

diphenhydrAMINE has a major potential interaction with Depression.

A variety of abnormal thinking and behavior changes have been reported to occur in association with the use of most anxiolytics, sedatives and hypnotics. Some of these changes include decreased inhibition, aggressiveness, agitation, and hallucinations. These drugs can cause or exacerbate mental depression and cause suicidal behavior and ideation. Therapy with these drugs should be administered cautiously in patients with a history of depression or other psychiatric disorders. Patients should be monitored for any changes in mood or behavior. It may be prudent to refrain from dispensing large quantities of medication to these patients.

Drug Dependence

Major:

pentazocine

Pentazocine has a major potential interaction with Drug Dependence.

Opioid partial agonists have the potential to cause dependence and abuse, particularly in patients with a history of drug abuse. Tolerance as well as physical and psychological dependence can develop after prolonged use, and abrupt cessation or a significant reduction in dosage may precipitate withdrawal symptoms. Because of their opioid antagonistic effect, withdrawal symptoms may also occur if opioid partial agonists are administered to patients with an opioid dependence or in whom substantial amounts of narcotics have recently been administered. Therapy with opioid partial agonists is not recommended in patients who are physically dependent on narcotics. Addiction-prone individuals, such as those with a history of alcohol or substance abuse, should be under careful surveillance or medical supervision when treated with opioid partial agonists. It may be prudent to refrain from dispensing large quantities of medication to these patients. After prolonged use or if dependency is suspected, withdrawal of opioid therapy should be undertaken gradually using a dosage-tapering schedule.

Gallbladder Disease

Moderate:

pentazocine

Pentazocine has a moderate potential interaction with Gallbladder Disease.

Opioid agonists may cause spasm of the sphincter of Oddi, which may increase biliary tract pressure. Other opioid-induced effects may include a reduction in biliary and pancreatic secretions and transient elevations in serum amylase. Patients with biliary tract disease (including acute pancreatitis) should be regularly evaluated for worsening symptoms. Therapy with opioids should be administered cautiously in patients with biliary tract disease, gallbladder disease, or acute pancreatitis.

Gastrointestinal Obstruction

Major:

pentazocine

Pentazocine has a major potential interaction with Gastrointestinal Obstruction.

Opioid analgesics are contraindicated in patients with known or suspected gastrointestinal obstruction, including paralytic ileus.

Major:

pentazocine

Pentazocine has a major potential interaction with Gastrointestinal Obstruction.

Narcotic (opioid) analgesic agents increase smooth muscle tone in the gastrointestinal tract and decrease peristalsis, which can lead to elevated intraluminal pressure, spasm, and constipation following prolonged use. In patients with severe or acute inflammatory bowel disease, the decrease in colonic motility may induce toxic megacolon. Therapy with opioids should be administered cautiously in patients with gastrointestinal obstruction, constipation, inflammatory bowel disease, or recent gastrointestinal tract surgery. Gastrointestinal effects appear to be the most pronounced with morphine.

Moderate:

diphenhydramine

diphenhydrAMINE has a moderate potential interaction with Gastrointestinal Obstruction.

Antihistamines often have anticholinergic activity, to which elderly patients are particularly sensitive. Therapy with antihistamines should be administered cautiously, if at all, in patients with preexisting conditions that are likely to be exacerbated by anticholinergic activity, such as urinary retention or obstruction; angle-closure glaucoma, untreated intraocular hypertension, or uncontrolled primary open-angle glaucoma; and gastrointestinal obstructive disorders. Conventional, first-generation antihistamines such as the ethanolamines (bromodiphenhydramine, carbinoxamine, clemastine, dimenhydrinate, diphenhydramine, doxylamine, phenyltoloxamine) tend to exhibit substantial anticholinergic effects. In contrast, the newer, relatively nonsedating antihistamines (e.g., cetirizine, fexofenadine, loratadine) reportedly have low to minimal anticholinergic activity at normally recommended dosages and may be appropriate alternatives.

Glaucoma/Intraocular Hypertension

Moderate:

diphenhydramine

diphenhydrAMINE has a moderate potential interaction with Glaucoma/Intraocular Hypertension.

Antihistamines often have anticholinergic activity, to which elderly patients are particularly sensitive. Therapy with antihistamines should be administered cautiously, if at all, in patients with preexisting conditions that are likely to be exacerbated by anticholinergic activity, such as urinary retention or obstruction; angle-closure glaucoma, untreated intraocular hypertension, or uncontrolled primary open-angle glaucoma; and gastrointestinal obstructive disorders. Conventional, first-generation antihistamines such as the ethanolamines (bromodiphenhydramine, carbinoxamine, clemastine, dimenhydrinate, diphenhydramine, doxylamine, phenyltoloxamine) tend to exhibit substantial anticholinergic effects. In contrast, the newer, relatively nonsedating antihistamines (e.g., cetirizine, fexofenadine, loratadine) reportedly have low to minimal anticholinergic activity at normally recommended dosages and may be appropriate alternatives.

Moderate:

diphenhydramine

diphenhydrAMINE has a moderate potential interaction with Glaucoma/Intraocular Hypertension.

Some hypnotic drugs can have an anticholinergic effect and should be used with caution in patients with glaucoma, and trouble urinating due to retention or enlarged prostate.

Head Injury

Major:

pentazocine

Pentazocine has a major potential interaction with Head Injury.

The hypoventilation associated with administration of opioid partial agonists can induce cerebral hypoxia and vasodilatation with resultant increase in intracranial pressure. Unless mechanical ventilation is provided, extreme caution is advised when opioid partial agonists are given to patients with head injury, intracranial lesions, or a preexisting elevated CSF pressure. Also, clinicians treating such patients should be aware that opioid partial agonists may interfere with the evaluation of CNS function, especially with respect to consciousness levels, respiratory status, and pupillary changes.

Major:

pentazocine

Pentazocine has a major potential interaction with Head Injury.

Opioid partial agonists may produce respiratory depression by decreasing respiratory drive and increasing airway resistance. A "ceiling effect" has been noted for these agents and increasing doses do not produce proportional or further respiratory depression. However, the duration of effect is prolonged. At therapeutic analgesic dosages, the respiratory effects are usually not clinically important except in patients with preexisting pulmonary impairment. Therapy with opioid partial agonists should be avoided or administered with extreme caution and initiated at reduced dosages in patients with severe CNS or respiratory depression; acute alcohol intoxication; sleep apnea; hypoxia, anoxia, or hypercapnia; upper airway obstruction; chronic pulmonary insufficiency; a limited ventilatory reserve; or other respiratory disorders. In the presence of excessive respiratory secretions, the use of opioid partial agonists may also be problematic because they decrease ciliary activity and reduce the cough reflex. Caution is also advised in patients who may be at increased risk for respiratory depression, such as comatose patients or those with head injury, intracranial lesions, or intracranial hypertension. Clinical monitoring of pulmonary function is recommended, and equipment for resuscitation should be immediately available if parenteral routes are used. Naloxone may be administered to reverse clinically significant respiratory depression.

Hyperthyroidism

Moderate:

diphenhydramine

diphenhydrAMINE has a moderate potential interaction with Hyperthyroidism.

Antihistamines may infrequently cause cardiovascular adverse effects related to their anticholinergic and local anesthetic (quinidine-like) activities. Tachycardia, palpitation, ECG changes, arrhythmias, hypotension, and hypertension have been reported. Although these effects are uncommon and usually limited to overdosage situations, the manufacturers and some clinicians recommend that therapy with antihistamines be administered cautiously in patients with cardiovascular disease, hypertension, and/or hyperthyroidism.

Hypotension

Moderate:

diphenhydramine

diphenhydrAMINE has a moderate potential interaction with Hypotension.

Antihistamines may infrequently cause cardiovascular adverse effects related to their anticholinergic and local anesthetic (quinidine-like) activities. Tachycardia, palpitation, ECG changes, arrhythmias, hypotension, and hypertension have been reported. Although these effects are uncommon and usually limited to overdosage situations, the manufacturers and some clinicians recommend that therapy with antihistamines be administered cautiously in patients with cardiovascular disease, hypertension, and/or hyperthyroidism.

Infectious Gastroenteritis

Major:

pentazocine

Pentazocine has a major potential interaction with Infectious Gastroenteritis.

Narcotic (opioid) analgesic agents may prolong and/or worsen diarrhea associated with organisms that invade the intestinal mucosa, such as toxigenic Escherichia coli, Salmonella, Shigella, and pseudomembranous colitis due to broad-spectrum antibiotics. These agents decrease gastrointestinal motility, which may delay the excretion of infective gastroenteric organisms and/or their toxins. Other symptoms and complications such as fever, shedding of organisms, and extraintestinal illness may also be increased or prolonged. Therapy with opioids should be avoided or administered cautiously in patients with infectious diarrhea, particularly that due to pseudomembranous enterocolitis or enterotoxin-producing bacteria or if accompanied by high fever, pus, or blood in the stool.

Inflammatory Bowel Disease

Major:

pentazocine

Pentazocine has a major potential interaction with Inflammatory Bowel Disease.

Narcotic (opioid) analgesic agents increase smooth muscle tone in the gastrointestinal tract and decrease peristalsis, which can lead to elevated intraluminal pressure, spasm, and constipation following prolonged use. In patients with severe or acute inflammatory bowel disease, the decrease in colonic motility may induce toxic megacolon. Therapy with opioids should be administered cautiously in patients with gastrointestinal obstruction, constipation, inflammatory bowel disease, or recent gastrointestinal tract surgery. Gastrointestinal effects appear to be the most pronounced with morphine.

Intestinal Anastomoses

Major:

pentazocine

Pentazocine has a major potential interaction with Intestinal Anastomoses.

Narcotic (opioid) analgesic agents increase smooth muscle tone in the gastrointestinal tract and decrease peristalsis, which can lead to elevated intraluminal pressure, spasm, and constipation following prolonged use. In patients with severe or acute inflammatory bowel disease, the decrease in colonic motility may induce toxic megacolon. Therapy with opioids should be administered cautiously in patients with gastrointestinal obstruction, constipation, inflammatory bowel disease, or recent gastrointestinal tract surgery. Gastrointestinal effects appear to be the most pronounced with morphine.

Ischemic Heart Disease

Major:

pentazocine

Pentazocine has a major potential interaction with Ischemic Heart Disease.

Opioid partial agonists may increase systemic and pulmonary arterial pressure and systemic vascular resistance, particularly when given by IV administration. Data are available for pentazocine and butorphanol. Therapy with opioid partial agonists should be administered cautiously and only if the benefit justifies the risk in patients with acute myocardial infarction (especially if accompanied by hypertension or left ventricular failure) or coronary insufficiency.

Liver Disease

Moderate:

diphenhydramine

diphenhydrAMINE has a moderate potential interaction with Liver Disease.

Limited pharmacokinetic data are available for the older, first-generation antihistamines. Many appear to be primarily metabolized by the liver, and both parent drugs and metabolites are excreted in the urine. Patients with renal and/or liver disease may be at greater risk for adverse effects from antihistamines due to drug and metabolite accumulation. Therapy with antihistamines should be administered cautiously in such patients. Lower initial dosages may be appropriate.

Moderate:

diphenhydramine

diphenhydrAMINE has a moderate potential interaction with Liver Disease.

In general, anxiolytics, sedatives and hypnotics are extensively metabolized by the liver. Their plasma clearance may be decreased and their half-life prolonged in patients with impaired hepatic function. Therapy with these drugs should be administered cautiously in patients with liver disease (some are not recommended in severe liver impairment), and the dosage should be adjusted accordingly. Laboratory testing is recommended prior and during treatment.

Moderate:

pentazocine

Pentazocine has a moderate potential interaction with Liver Disease.

Narcotic (opioid) analgesic agents are extensively metabolized by the liver, and several of them (e.g., codeine, hydrocodone, meperidine, methadone, morphine, propoxyphene) have active metabolites that are further converted to inactive substances. The serum concentrations of these agents and their metabolites may be increased and the half-lives prolonged in patients with impaired hepatic function. Therapy with opioids should be administered cautiously and initiated at reduced dosages in patients with liver disease. Subsequent doses should be titrated based on individual response rather than a fixed dosing schedule.

Pancreatitis

Moderate:

pentazocine

Pentazocine has a moderate potential interaction with Pancreatitis.

Opioid agonists may cause spasm of the sphincter of Oddi, which may increase biliary tract pressure. Other opioid-induced effects may include a reduction in biliary and pancreatic secretions and transient elevations in serum amylase. Patients with biliary tract disease (including acute pancreatitis) should be regularly evaluated for worsening symptoms. Therapy with opioids should be administered cautiously in patients with biliary tract disease, gallbladder disease, or acute pancreatitis.

Prematurity/Underweight in Infancy

Major:

pentazocine

Pentazocine has a major potential interaction with Prematurity/Underweight in Infancy.

The use of narcotic (opioid) analgesic agents is contraindicated in premature infants. These agents may cross the immature blood-brain barrier to a greater extent than in adults, resulting in disproportionate respiratory depression.

Pulmonary Impairment

Major:

pentazocine

Pentazocine has a major potential interaction with Pulmonary Impairment.

Opioid partial agonists may produce respiratory depression by decreasing respiratory drive and increasing airway resistance. A "ceiling effect" has been noted for these agents and increasing doses do not produce proportional or further respiratory depression. However, the duration of effect is prolonged. At therapeutic analgesic dosages, the respiratory effects are usually not clinically important except in patients with preexisting pulmonary impairment. Therapy with opioid partial agonists should be avoided or administered with extreme caution and initiated at reduced dosages in patients with severe CNS or respiratory depression; acute alcohol intoxication; sleep apnea; hypoxia, anoxia, or hypercapnia; upper airway obstruction; chronic pulmonary insufficiency; a limited ventilatory reserve; or other respiratory disorders. In the presence of excessive respiratory secretions, the use of opioid partial agonists may also be problematic because they decrease ciliary activity and reduce the cough reflex. Caution is also advised in patients who may be at increased risk for respiratory depression, such as comatose patients or those with head injury, intracranial lesions, or intracranial hypertension. Clinical monitoring of pulmonary function is recommended, and equipment for resuscitation should be immediately available if parenteral routes are used. Naloxone may be administered to reverse clinically significant respiratory depression.

Renal Dysfunction

Moderate:

diphenhydramine

diphenhydrAMINE has a moderate potential interaction with Renal Dysfunction.

Limited pharmacokinetic data are available for the older, first-generation antihistamines. Many appear to be primarily metabolized by the liver, and both parent drugs and metabolites are excreted in the urine. Patients with renal and/or liver disease may be at greater risk for adverse effects from antihistamines due to drug and metabolite accumulation. Therapy with antihistamines should be administered cautiously in such patients. Lower initial dosages may be appropriate.

Moderate:

pentazocine

Pentazocine has a moderate potential interaction with Renal Dysfunction.

Although narcotic (opioid) analgesic agents are generally metabolized by the liver, renal impairment can alter the elimination of these agents and their metabolites (some of which are pharmacologically active), resulting in drug accumulation and increased risk of toxicity. Therapy with opioids should be administered cautiously and initiated at reduced dosages in patients with significantly impaired renal function. Subsequent doses should be titrated based on individual response rather than a fixed dosing schedule.

Respiratory Arrest

Major:

pentazocine

Pentazocine has a major potential interaction with Respiratory Arrest.

Opioid partial agonists may produce respiratory depression by decreasing respiratory drive and increasing airway resistance. A "ceiling effect" has been noted for these agents and increasing doses do not produce proportional or further respiratory depression. However, the duration of effect is prolonged. At therapeutic analgesic dosages, the respiratory effects are usually not clinically important except in patients with preexisting pulmonary impairment. Therapy with opioid partial agonists should be avoided or administered with extreme caution and initiated at reduced dosages in patients with severe CNS or respiratory depression; acute alcohol intoxication; sleep apnea; hypoxia, anoxia, or hypercapnia; upper airway obstruction; chronic pulmonary insufficiency; a limited ventilatory reserve; or other respiratory disorders. In the presence of excessive respiratory secretions, the use of opioid partial agonists may also be problematic because they decrease ciliary activity and reduce the cough reflex. Caution is also advised in patients who may be at increased risk for respiratory depression, such as comatose patients or those with head injury, intracranial lesions, or intracranial hypertension. Clinical monitoring of pulmonary function is recommended, and equipment for resuscitation should be immediately available if parenteral routes are used. Naloxone may be administered to reverse clinically significant respiratory depression.

Seizures

Moderate:

pentazocine

Pentazocine has a moderate potential interaction with Seizures.

Narcotic (opioid) analgesic agents may increase the frequency of seizures in patients with seizure disorders, may increase the risk of seizures occurring in other clinical settings associated with seizures, and, at higher dosages, have been reported to induce seizures in patients without history of seizures. Patients with history of seizure disorders should be regularly evaluated for worsened seizure control during therapy. Prolonged meperidine use may increase the risk of toxicity (e.g., seizures) from the accumulation of the active metabolite (normeperidine).

Urinary Retention

Moderate:

diphenhydramine

diphenhydrAMINE has a moderate potential interaction with Urinary Retention.

Antihistamines often have anticholinergic activity, to which elderly patients are particularly sensitive. Therapy with antihistamines should be administered cautiously, if at all, in patients with preexisting conditions that are likely to be exacerbated by anticholinergic activity, such as urinary retention or obstruction; angle-closure glaucoma, untreated intraocular hypertension, or uncontrolled primary open-angle glaucoma; and gastrointestinal obstructive disorders. Conventional, first-generation antihistamines such as the ethanolamines (bromodiphenhydramine, carbinoxamine, clemastine, dimenhydrinate, diphenhydramine, doxylamine, phenyltoloxamine) tend to exhibit substantial anticholinergic effects. In contrast, the newer, relatively nonsedating antihistamines (e.g., cetirizine, fexofenadine, loratadine) reportedly have low to minimal anticholinergic activity at normally recommended dosages and may be appropriate alternatives.

Moderate:

diphenhydramine

diphenhydrAMINE has a moderate potential interaction with Urinary Retention.

Some hypnotic drugs can have an anticholinergic effect and should be used with caution in patients with glaucoma, and trouble urinating due to retention or enlarged prostate.

Moderate:

pentazocine

Pentazocine has a moderate potential interaction with Urinary Retention.

Narcotic (opioid) analgesic agents may inhibit the urinary voiding reflex and increase the tone of the vesical sphincter in the bladder. Acute urinary retention requiring catheterization may occur, particularly in patients with prostatic hypertrophy or urethral stricture and in older adult patients. These agents may also decrease urine production via direct effects on the kidney and central stimulation of the release of vasopressin. Therapy with opioids should be administered cautiously in patients with or predisposed to urinary retention and/or oliguria. The effects on smooth muscle tone appear to be the most pronounced with morphine.

More resources

diphenhydramine

A total of 493 drugs are known to interact with diphenhydramine.

pentazocine

A total of 472 drugs are known to interact with pentazocine.

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.