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Drug Interactions between Extendryl PEM and Nizoral

This report displays the potential drug interactions for the following 2 drugs:

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Interactions between your drugs

Moderate

ketoconazole methscopolamine

Applies to: Nizoral (ketoconazole) and Extendryl PEM (methscopolamine / phenylephrine)

ADJUST DOSING INTERVAL: Theoretically, anticholinergic agents can reduce gastric acid secretion and reduce the oral bioavailability of ketoconazole, which requires an acidic environment for dissolution and absorption.

MANAGEMENT: Anticholinergic agents should be administered at least 2 hours after ketoconazole.

References

  1. (2002) "Product Information. Nizoral (ketoconazole)." Janssen Pharmaceuticals
  2. (2022) "Product Information. Recorlev (levoketoconazole)." Xeris Pharmaceuticals Inc
  3. Auchus R, Pivonello R, Fleseriu M, et al. (2022) Levoketoconazole: a novel treatment for endogenous Cushing's syndrome. https://www.tandfonline.com/doi/pdf/10.1080/17446651.2021.1945440

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Moderate

phenylephrine methscopolamine

Applies to: Extendryl PEM (methscopolamine / phenylephrine) and Extendryl PEM (methscopolamine / phenylephrine)

MONITOR: The pressor response to phenylephrine may be potentiated by the vagolytic effect of atropine, which inhibits the reflex bradycardia that would normally accompany any increases in blood pressure induced by phenylephrine. Other antimuscarinic agents may also participate in this interaction, although clinical data are lacking. In one report, pseudo-pheochromocytoma (i.e., significant increases in blood pressure and tachycardia) occurred in seven patients who underwent eye surgery and were given phenylephrine 10% ophthalmic solution and systemic atropine, three of whom subsequently developed left ventricular failure and pulmonary edema that required intensive care monitoring. Two patients had preexisting hypertension, while others had no known history of cardiovascular disease. All had received general anesthesia with propofol, phenoperidine, and vecuronium. Since phenylephrine use alone may be associated with cardiovascular toxicities including hypertension, arrhythmia, myocardial infarction and cardiac failure, the extent of involvement by atropine is uncertain. The authors reported no further cardiovascular events following implementation of various measures that reduced phenylephrine dosage and systemic exposure, including: use of a milder strength of phenylephrine ophthalmic solution; swabbing to minimize drainage into the nasolachrymal duct to the nasal mucosa; and use of a cannula to reduce drop size. In a study of six healthy volunteers, diastolic and systolic blood pressure increased by 4 mmHg following administration of phenylephrine (0.42 mcg/kg/min), compared to 17 mmHg when phenylephrine was given after three doses of atropine (0.02, 0.01 and 0.01 mg/kg at 30 minute intervals).

MANAGEMENT: Caution is advised if phenylephrine (systemic or ophthalmic) is used in combination with atropine or other antimuscarinic agents. Cardiovascular status, including blood pressure and heart rate, should be closely monitored. When using ophthalmic formulations, measures to minimize systemic absorption should be employed, such as digital compression of the lacrimal sac or lid closure after instillation. A milder strength (< 10%) is preferable if phenylephrine ophthalmic solution is given.

References

  1. Daelman F, Andrejak M, Rajaonarivony D, Bryselbout E, Jezraoui P, Ossart M (1994) "Phenylephrine eyedrops, systemic atropine and cardiovascular adverse events." Therapie, 49, p. 467
  2. Fraunfelder FT, Fraunfelder FW; Randall JA (2001) "Drug-Induced Ocular Side Effects" Boston, MA: Butterworth-Heinemann
  3. Lai YK (1989) "Adverse effect of intraoperative phenylephrine 10%: case report." Br J Ophthalmol, 73, p. 468-9
  4. Van Der Spek AF, Hantler CB (1986) "Phenylephrine eyedrops and anesthesia." Anesthesiology, 64, p. 812-4
  5. Levine MA, Leenen FH (1992) "Role of vagal activity in the cardiovascular responses to phenylephrine in man." Br J Clin Pharmacol, 33, p. 333-6
View all 5 references

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Drug and food interactions

Moderate

ketoconazole food

Applies to: Nizoral (ketoconazole)

GENERALLY AVOID: Excessive use of alcohol or products containing alcohol together with ketoconazole or levoketoconazole may potentiate the risk of liver injury. Serious hepatotoxicity has been reported with levoketoconazole. Hepatotoxicity requiring liver transplantation has been reported with the use of oral ketoconazole, of which levoketoconazole is an enantiomer. Some patients had no obvious risk factors for liver disease. In addition, use of alcohol or products containing alcohol during ketoconazole or levoketoconazole therapy may result in a disulfiram-like reaction in some patients. Symptoms of disulfiram-like reaction include flushing, rash, peripheral edema, nausea, and headache.

GENERALLY AVOID: Coadministration with grapefruit juice may increase the plasma concentrations of ketoconazole or levoketoconazole. The mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. Inhibition of hepatic CYP450 3A4 may also contribute. In general, the effect of grapefruit juice is concentration-, dose- and preparation-dependent, and can vary widely among brands. Certain preparations of grapefruit juice (e.g., high dose, double strength) have sometimes demonstrated potent inhibition of CYP450 3A4, while other preparations (e.g., low dose, single strength) have typically demonstrated moderate inhibition. Pharmacokinetic interactions involving grapefruit juice are also subject to a high degree of interpatient variability, thus the extent to which a given patient may be affected is difficult to predict.

When administered to healthy volunteers with a high-fat meal (875 calories; 62% fat), levoketoconazole systemic exposure (AUC) increased by 30% while peak plasma concentration (Cmax) did not change and the time to reach Cmax (Tmax) was delayed from 2 to 4 hours, compared to fasted conditions.

MANAGEMENT: Levoketoconazole may be administered with or without food. Excessive consumption of alcohol should generally be avoided during ketoconazole or levoketoconazole therapy. Patients should preferably avoid or limit consumption of grapefruit, grapefruit juice, or any supplement containing grapefruit extract during ketoconazole or levoketoconazole therapy. Patients receiving ketoconazole or levoketoconazole should be instructed to contact their doctor immediately if they experience swelling, skin rash, itching, loss of appetite, fatigue, nausea, vomiting, abdominal pain, dark colored urine, light colored stools, and/or yellowing of the skin or eyes, as these may be signs and symptoms of liver damage.

References

  1. (2019) "Product Information. Ketoconazole (ketoconazole)." Mylan Pharmaceuticals Inc
  2. (2022) "Product Information. Recorlev (levoketoconazole)." Xeris Pharmaceuticals Inc
  3. Auchus R, Pivonello R, Fleseriu M, et al. (2022) Levoketoconazole: a novel treatment for endogenous Cushing's syndrome. https://www.tandfonline.com/doi/pdf/10.1080/17446651.2021.1945440
  4. (2021) "Product Information. Ketoconazole (ketoconazole)." Burel Pharmaceuticals Inc
View all 4 references

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Moderate

methscopolamine food

Applies to: Extendryl PEM (methscopolamine / phenylephrine)

GENERALLY AVOID: Use of anticholinergic agents with alcohol may result in sufficient impairment of attention so as to render driving and operating machinery more hazardous. In addition, the potential for abuse may be increased with the combination. The mechanism of interaction is not established but may involve additive depressant effects on the central nervous system. No effect of oral propantheline or atropine on blood alcohol levels was observed in healthy volunteers when administered before ingestion of a standard ethanol load. However, one study found impairment of attention in subjects given atropine 0.5 mg or glycopyrrolate 1 mg in combination with alcohol.

MANAGEMENT: Alcohol should generally be avoided during therapy with anticholinergic agents. Patients should be counseled to avoid activities requiring mental alertness until they know how these agents affect them.

References

  1. Linnoila M (1973) "Drug effects on psychomotor skills related to driving: interaction of atropine, glycopyrrhonium and alcohol." Eur J Clin Pharmacol, 6, p. 107-12

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Moderate

phenylephrine food

Applies to: Extendryl PEM (methscopolamine / phenylephrine)

MONITOR: Coadministration of two or more sympathomimetic agents may increase the risk of adverse effects such as nervousness, irritability, and increased heart rate. Central nervous system (CNS) stimulants, particularly amphetamines, can potentiate the adrenergic response to vasopressors and other sympathomimetic agents. Additive increases in blood pressure and heart rate may occur due to enhanced peripheral sympathetic activity.

MANAGEMENT: Caution is advised if two or more sympathomimetic agents are coadministered. Pulse and blood pressure should be closely monitored.

References

  1. Rosenblatt JE, Lake CR, van Kammen DP, Ziegler MG, Bunney WE Jr (1979) "Interactions of amphetamine, pimozide, and lithium on plasma norepineophrine and dopamine-beta-hydroxylase in schizophrenic patients." Psychiatry Res, 1, p. 45-52
  2. Cavanaugh JH, Griffith JD, Oates JA (1970) "Effect of amphetamine on the pressor response to tyramine: formation of p-hydroxynorephedrine from amphetamine in man." Clin Pharmacol Ther, 11, p. 656
  3. (2001) "Product Information. Adderall (amphetamine-dextroamphetamine)." Shire Richwood Pharmaceutical Company Inc
  4. (2001) "Product Information. Tenuate (diethylpropion)." Aventis Pharmaceuticals
  5. (2001) "Product Information. Sanorex (mazindol)." Novartis Pharmaceuticals
  6. (2001) "Product Information. Focalin (dexmethylphenidate)." Mikart Inc
  7. (2002) "Product Information. Strattera (atomoxetine)." Lilly, Eli and Company
View all 7 references

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Therapeutic duplication warnings

No warnings were found for your selected drugs.

Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.


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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.