Interactions between Flavoxate and Scopolamine
1 drug interaction and 26 additional warnings found for the following 2 drugs:
- flavoxate
- scopolamine
Drug interactions
Moderate drug interactions
Moderate:
scopolamine flavoxATE
Applies to: scopolamine and flavoxate
Monitor
Agents with anticholinergic properties (e.g., sedating antihistamines; antispasmodics; neuroleptics; phenothiazines; skeletal muscle relaxants; tricyclic antidepressants; disopyramide) may have additive effects when used in combination. Excessive parasympatholytic effects may result in paralytic ileus, hyperthermia, heat stroke, and the anticholinergic intoxication syndrome. Peripheral symptoms of intoxication commonly include mydriasis, blurred vision, flushed face, fever, dry skin and mucous membranes, tachycardia, urinary retention, and constipation. Central symptoms may include memory loss, disorientation, incoherence, hallucinations, psychosis, delirium, hyperactivity, twitching or jerking movements, stereotypy, and seizures. Central nervous system-depressant effects may also be additively or synergistically increased when these agents are combined, especially in elderly or debilitated patients. Use of neuroleptics in combination with other neuroleptics or anticholinergic agents may increase the risk of tardive dyskinesia. In addition, some neuroleptics and tricyclic antidepressants may cause prolongation of the QT interval and theoretically, concurrent use of two or more drugs that can cause QT interval prolongation may result in additive effects and increased risk of ventricular arrhythmias including torsade de pointes and sudden death.
Management
Caution is advised when agents with anticholinergic properties are combined, particularly in the elderly and those with underlying organic brain disease, who tend to be more sensitive to the central anticholinergic effects of these drugs and in whom toxicity symptoms may be easily overlooked. Patients should be advised to notify their physician promptly if they experience potential symptoms of anticholinergic intoxication such as abdominal pain, fever, heat intolerance, blurred vision, confusion, and/or hallucinations. Ambulatory patients should be counseled to avoid activities requiring mental alertness until they know how these agents affect them. A reduction in anticholinergic dosages may be necessary if excessive adverse effects develop.
References (15)
- Stadnyk AN, Glezos JD (1983) "Drug-induced heat stroke." Can Med Assoc J, 128, p. 957-9
- Zelman S, Guillan R (1970) "Heat stroke in phenothiazine-treated patients: a report of three fatalities." Am J Psychiatry, 126, p. 1787-90
- Mann SC, Boger WP (1978) "Psychotropic drugs, summer heat and humidity, and hyperplexia: a danger restated." Am J Psychiatry, 135, p. 1097-100
- Warnes H, Lehmann HE, Ban TA (1967) "Adynamic ileus during psychoactive medication: a report of three fatal and five severe cases." Can Med Assoc J, 96, p. 1112-3
- Gershon S, Neubauer H, Sundland DM (1965) "Interaction between some anticholinergic agents and phenothiazines." Clin Pharmacol Ther, 6, p. 749-56
- Sarnquist F, Larson CP Jr (1973) "Drug-induced heat stroke." Anesthesiology, 39, p. 348-50
- Johnson AL, Hollister LE, Berger PA (1981) "The anticholinergic intoxication syndrome: diagnosis and treatment." J Clin Psychiatry, 42, p. 313-7
- Lee BS (1986) "Possibility of hyperpyrexia with antipsychotic and anticholinergic drugs." J Clin Psychiatry, 47, p. 571
- Forester D (1978) "Fatal drug-induced heat stroke." JACEP, 7, p. 243-4
- Moreau A, Jones BD, Banno V (1986) "Chronic central anticholinergic toxicity in manic depressive illness mimicking dementia." Can J Psychiatry, 31, p. 339-41
- Hvizdos AJ, Bennett JA, Wells BG, Rappaport KB, Mendel SA (1983) "Anticholinergic psychosis in a patient receiving usual doses of haloperidol." Clin Pharm, 2, p. 174-8
- Cohen MA, Alfonso CA, Mosquera M (1994) "Development of urinary retention during treatment with clozapine and meclizine [published erratum appears in Am J Psychiatry 1994 Jun;151(6):952]." Am J Psychiatry, 151, p. 619-20
- (2001) "Product Information. Cogentin (benztropine)." Merck & Co., Inc
- Kulik AV, Wilbur R (1982) "Delirium and stereotypy from anticholinergic antiparkinson drugs." Prog Neuropsychopharmacol Biol Psychiatry, 6, p. 75-82
- (2001) "Product Information. Artane (trihexyphenidyl)." Lederle Laboratories
Therapeutic duplication warnings
Therapeutic duplication is the use of more than one medicine from the same drug category or therapeutic class to treat the same condition.
It can be intentional, when combining drugs with similar actions adds demonstrated therapeutic benefit — or unintentional, such as when a patient sees multiple prescribers or fills prescriptions at more than one pharmacy, which can lead to adverse effects.
Duplication:
Anticholinergics/antispasmodics
The recommended maximum number of medicines in the 'anticholinergics/antispasmodics' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'anticholinergics/antispasmodics' category:
- flavoxate
- scopolamine
Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.
Food/lifestyle interactions
Moderate food/lifestyle interactions
Moderate:
flavoxATE Food/Lifestyle
Applies to: flavoxate
Generally avoid
Alcohol may potentiate some of the pharmacologic effects of CNS-active agents. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.
Management
Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol. Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.
References (4)
- Warrington SJ, Ankier SI, Turner P (1986) "Evaluation of possible interactions between ethanol and trazodone or amitriptyline." Neuropsychobiology, 15, p. 31-7
- Gilman AG, eds., Nies AS, Rall TW, Taylor P (1990) "Goodman and Gilman's the Pharmacological Basis of Therapeutics." New York, NY: Pergamon Press Inc.
- (2012) "Product Information. Fycompa (perampanel)." Eisai Inc
- (2015) "Product Information. Rexulti (brexpiprazole)." Otsuka America Pharmaceutical, Inc.
Moderate:
scopolamine Alcohol (Ethanol)
Applies to: scopolamine
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
Minor food/lifestyle interactions
Minor:
scopolamine Food/Lifestyle
Applies to: scopolamine
The coadministration with grapefruit juice may delay the absorption and increase the bioavailability of oral scopolamine. The proposed mechanism is delay of gastric emptying as well as inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall induced by certain compounds present in grapefruits. In an open-label, crossover study consisting of 14 subjects, the consumption of grapefruit juice (compared to water) was associated with a 30% increase in mean systemic bioavailability and a 153% increase in time to reach peak serum concentration (Tmax) of scopolamine. However, the perceived pharmacodynamic effect of the drug, as measured by % change in subjective alertness compared to baseline, was similar after coadministration with water and grapefruit juice. Based on these findings, grapefruit juice is unlikely to affect the overall safety profile of of scopolamine but may delay its onset of action following oral administration. However, as with other drug interactions involving grapefruit juice, the pharmacokinetic alterations are subject to a high degree of interpatient variability.
References (1)
- Ebert U, Oertel R, Kirch W (2000) "Influence of grapefruit juice on scopolamine pharmacokinetics and pharmacodynamics in healthy male and female subjects." Int J Clin Pharm Therapeutics, 38, p. 523-31
Disease interactions
22 potential interactions Applies to: 18 conditions, including High Blood Pressure, GERD, Asthma, Diarrhea, and Arrhythmia.
Arrhythmia
Moderate:
scopolamine
Scopolamine has a moderate potential interaction with Arrhythmia.
Anticholinergics block vagal inhibition of the SA nodal pacemaker. Therapy with anticholinergics should be administered cautiously in patients with tachycardia, congestive heart failure, or coronary artery disease. Premature ventricular depolarization or ventricular tachycardia or fibrillation associated with anticholinergics is rare.
Moderate:
scopolamine
Scopolamine has a moderate potential interaction with Arrhythmia.
Antimuscarinic agents block vagal inhibition of the SA nodal pacemaker. These agents should be administered cautiously in patients with tachycardia, congestive heart failure, or coronary artery disease. Premature ventricular depolarization or ventricular tachycardia or fibrillation associated with antimuscarinic drugs is rare.
Asthma
Major:
scopolamine
Scopolamine has a major potential interaction with Asthma.
The use of systemic anticholinergics is contraindicated in the treatment of lower respiratory tract symptoms including asthma. Muscarinic receptor antagonists reduce bronchial secretions, which can result in decreased fluidity and increased thickening of secretions. However, ipratropium does not produce these effects and can be used safely in treating asthma.
Autonomic Neuropathy
Major:
scopolamine
Scopolamine has a major potential interaction with Autonomic Neuropathy.
Agents with anticholinergic activity can exacerbate many of the manifestations of autonomic neuropathy, including tachycardia, anhidrosis, bladder atony, obstipation, dry mouth and eyes, cycloplegia and blurring of vision, and sexual impotence in males. Therapy with antimuscarinic agents and higher dosages of antispasmodic agents (e.g., dicyclomine or oxybutynin) should be administered cautiously in patients with autonomic neuropathy.
Bleeding Disorder
Moderate:
scopolamine
Scopolamine has a moderate potential interaction with Bleeding Disorder.
Antimuscarinic agents may cause a delay in gastric emptying and possibly antral stasis in patients with gastric ulcer. Therapy with antimuscarinic agents should be administered cautiously to patients with gastric ulcer.
Cardiovascular Conditions and Disorders
Moderate:
scopolamine
Scopolamine has a moderate potential interaction with Cardiovascular Conditions and Disorders.
Anticholinergics block vagal inhibition of the SA nodal pacemaker. Therapy with anticholinergics should be administered cautiously to patients with tachycardia, congestive heart failure, or coronary artery disease. Premature ventricular depolarization, ventricular tachycardia, and fibrillation associated with anticholinergics are rare.
Diarrhea
Minor:
scopolamine
Scopolamine has a minor potential interaction with Diarrhea.
Diarrhea may be a symptom of incomplete intestinal obstruction, especially in patients with ileostomy or colostomy. Antimuscarinic agents may further aggravate the diarrhea. Therefore, these drugs should be administered cautiously in patients with diarrhea.
Esophageal Obstruction
Major:
scopolamine
Scopolamine has a major potential interaction with Esophageal Obstruction.
Anticholinergics are contraindicated in patients with obstructive diseases such as achalasia, esophageal stricture or stenosis, pyloroduodenal stenosis, stenosing peptic ulcer, pyloric obstruction, and paralytic ileus. Anticholinergics may further suppress intestinal motility with resultant precipitation or aggravation of toxic megacolon.
Fever
Minor:
scopolamine
Scopolamine has a minor potential interaction with Fever.
Atropine-like agents may increase the risk of hyperthermia in patients with fever by producing anhidrosis. Therapy with atropine-like agents should be administered cautiously in febrile patients.
Gastrointestinal Obstruction
Major:
flavoxate
flavoxATE has a major potential interaction with Gastrointestinal Obstruction.
The use of flavoxate is contraindicated in patients with GI obstruction, ileus, atony, and obstructive uropathy. Flavoxate exerts direct antispasmodic effects on smooth muscles and possesses weak anticholinergic activity.
Major:
scopolamine
Scopolamine has a major potential interaction with Gastrointestinal Obstruction.
Anticholinergics are contraindicated in patients with obstructive diseases such as achalasia, esophageal stricture or stenosis, pyloroduodenal stenosis, stenosing peptic ulcer, pyloric obstruction, and paralytic ileus. Anticholinergics may further suppress intestinal motility with resultant precipitation or aggravation of toxic megacolon.
GERD
Moderate:
scopolamine
Scopolamine has a moderate potential interaction with GERD.
Antimuscarinic agents decrease gastric motility and relax the lower esophageal sphincter which promotes gastric retention and can aggravate reflux. These drugs should be administered cautiously in patients with gastroesophageal reflux or hiatal hernia associated with reflux esophagitis.
Glaucoma/Intraocular Hypertension
Major:
scopolamine
Scopolamine has a major potential interaction with Glaucoma/Intraocular Hypertension.
Anticholinergic agents are contraindicated in patients with primary glaucoma, a tendency toward glaucoma (narrow anterior chamber angle), or adhesions (synechiae) between the iris and lens, as well as for the elderly and others in whom undiagnosed glaucoma or excessive pressure in the eye may be present. Because anticholinergics cause mydriasis, they may exacerbate these conditions.
Moderate:
flavoxate
flavoxATE has a moderate potential interaction with Glaucoma/Intraocular Hypertension.
Flavoxate exerts mydriatic activity that can induce increased intraocular pressure and result in angle-closure (narrow angle) glaucoma. Therapy with flavoxate should be administered cautiously in patients with angle-closure glaucoma.
High Blood Pressure
Minor:
scopolamine
Scopolamine has a minor potential interaction with High Blood Pressure.
Cardiovascular effects of anticholinergics may exacerbate hypertension. Therapy with anticholinergic agents should be administered cautiously in patients with hypertension.
Hyperthyroidism
Minor:
scopolamine
Scopolamine has a minor potential interaction with Hyperthyroidism.
In general, agents with anticholinergic activity may exacerbate hyperthyroidism. Therapy with anticholinergics should be administered cautiously in patients with hyperthyroidism. Thyroid levels should be monitored if usage is prolonged.
Infectious Gastroenteritis
Major:
scopolamine
Scopolamine has a major potential interaction with Infectious Gastroenteritis.
The use of drugs with antiperistaltic activity (primarily antidiarrheal and antimuscarinic agents, but also antispasmodic agents such as dicyclomine or oxybutynin at high dosages) is contraindicated in patients with diarrhea due to pseudomembranous enterocolitis or enterotoxin-producing bacteria. These drugs may prolong and/or worsen diarrhea associated with organisms that invade the intestinal mucosa, such as toxigenic E. coli, Salmonella and Shigella, and pseudomembranous colitis due to broad-spectrum antibiotics. Other symptoms and complications such as fever, shedding of organisms and extraintestinal illness may also be increased or prolonged. In general, because antiperistaltic agents decrease gastrointestinal motility, they may delay the excretion of infective gastroenteric organisms or toxins and should be used cautiously in patients with any infectious diarrhea, particularly if accompanied by high fever or pus or blood in the stool. Some cough and cold and other combination products may occasionally include antimuscarinic agents for their drying effects and may, therefore, require careful selection when necessary.
Ischemic Heart Disease
Moderate:
scopolamine
Scopolamine has a moderate potential interaction with Ischemic Heart Disease.
Antimuscarinic agents block vagal inhibition of the SA nodal pacemaker. These agents should be administered cautiously in patients with tachycardia, congestive heart failure, or coronary artery disease. Premature ventricular depolarization or ventricular tachycardia or fibrillation associated with antimuscarinic drugs is rare.
Myasthenia Gravis
Major:
scopolamine
Scopolamine has a major potential interaction with Myasthenia Gravis.
Because antimuscarinic agents have anticholinergic effects, they are contraindicated in patients with myasthenia gravis. Their use may be appropriate to reduce adverse muscarinic effects caused by an anticholinesterase agent.
Ulcerative Colitis
Moderate:
scopolamine
Scopolamine has a moderate potential interaction with Ulcerative Colitis.
Antimuscarinic agents may suppress intestinal motility and produce paralytic ileus with resultant precipitation of toxic megacolon. These drugs should be administered cautiously to patients with ulcerative colitis.
Urinary Retention
Major:
flavoxate
flavoxATE has a major potential interaction with Urinary Retention.
The use of flavoxate is contraindicated in patients with GI obstruction, ileus, atony, and obstructive uropathy. Flavoxate exerts direct antispasmodic effects on smooth muscles and possesses weak anticholinergic activity.
Major:
scopolamine
Scopolamine has a major potential interaction with Urinary Retention.
In general, the use of anticholinergic agents is contraindicated in patients with urinary retention and bladder neck obstruction caused by prostatic hypertrophy. Dysuria may occur and may require catheterization. Also, anticholinergic drugs may aggravate partial obstructive uropathy. Caution is advised even when using agents with mild to moderate anticholinergic activity, particularly in elderly patients.
More resources
flavoxate
A total of 344 drugs are known to interact with flavoxate.
- Flavoxate is in the drug class urinary antispasmodics.
- Flavoxate is used to treat the following conditions:
scopolamine
A total of 365 drugs are known to interact with scopolamine.
- Scopolamine is in the following drug classes: anticholinergic antiemetics, anticholinergics/antispasmodics.
- Scopolamine is used to treat the following conditions:
Drug Interaction Classification
| Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
| Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
| 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. | |
| No interaction information available. |
Further information
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.