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Trimethobenzamide

Pronunciation

(trye meth oh BEN za mide)

Index Terms

  • Trimethobenzamide HCl
  • Trimethobenzamide Hydrochloride

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product

Capsule, Oral, as hydrochloride:

Tigan: 300 mg

Generic: 300 mg

Solution, Intramuscular, as hydrochloride:

Tigan: 100 mg/mL (2 mL)

Tigan: 100 mg/mL (20 mL) [contains phenol]

Generic: 100 mg/mL (2 mL [DSC], 20 mL [DSC])

Brand Names: U.S.

  • Tigan

Pharmacologic Category

  • Antiemetic

Pharmacology

Acts centrally to inhibit the medullary chemoreceptor trigger zone by blocking emetic impulses to the vomiting center

Metabolism

Via oxidation, forms metabolite trimethobenzamide N-oxide

Excretion

Urine (30% to 50%, as unchanged drug)

Onset of Action

Oral: 10 to 40 minutes; IM: 15 to 35 minutes

Time to Peak

Oral: ~45 minutes; IM: ~30 minutes

Duration of Action

Oral: 3 to 4 hours; IM: 2 to 3 hours

Half-Life Elimination

7 to 9 hours

Use: Labeled Indications

Nausea/vomiting: Treatment of postoperative nausea and vomiting; treatment of nausea associated with gastroenteritis

Contraindications

Hypersensitivity to trimethobenzamide or any component of the formulation; injection contraindicated in children

Dosing: Adult

Nausea/vomiting: Note: Use the lowest effective dosage based on response and tolerability.

Oral: 300 mg 3 or 4 times daily

IM: 200 mg 3 or 4 times daily

Dosing: Geriatric

Refer to adult dosing; increase the dosing interval and adjust as needed based on patient response.

Dosing: Renal Impairment

CrCl >70 mL/minute/1.73 m2: There are no dosage adjustments provided in the manufacturer's labeling.

CrCl ≤70 mL/minute/1.73 m2: Increase the dosing interval and adjust as needed based on patient response; monitor renal function closely.

Dosing: Hepatic Impairment

Avoid use in patients with hepatic impairment (due to potential risk of hepatotoxicity).

Administration

Injection: Administer IM only. Inject deep into upper outer quadrant of gluteal muscle. Not recommended for IV use.

Capsule: Administer capsule orally.

Storage

Store at 25°C (77°F); excursions are permitted between 15°C and 30°C (59°F and 86°F).

Drug Interactions

AbobotulinumtoxinA: Anticholinergic Agents may enhance the anticholinergic effect of AbobotulinumtoxinA. Monitor therapy

Acetylcholinesterase Inhibitors: May diminish the therapeutic effect of Anticholinergic Agents. Anticholinergic Agents may diminish the therapeutic effect of Acetylcholinesterase Inhibitors. Monitor therapy

Aclidinium: May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Alcohol (Ethyl): May enhance the CNS depressant effect of Trimethobenzamide. Monitor therapy

Amantadine: May enhance the anticholinergic effect of Anticholinergic Agents. Monitor therapy

Amifampridine: May diminish the anticholinergic effect of Anticholinergic Agents. Anticholinergic Agents may diminish the therapeutic effect of Amifampridine. Monitor therapy

Anticholinergic Agents: May enhance the adverse/toxic effect of other Anticholinergic Agents. Monitor therapy

Cannabinoid-Containing Products: Anticholinergic Agents may enhance the tachycardic effect of Cannabinoid-Containing Products. Exceptions: Cannabidiol. Monitor therapy

Chloral Betaine: May enhance the adverse/toxic effect of Anticholinergic Agents. Monitor therapy

Cimetropium: Anticholinergic Agents may enhance the anticholinergic effect of Cimetropium. Avoid combination

Eluxadoline: Anticholinergic Agents may enhance the constipating effect of Eluxadoline. Avoid combination

Gastrointestinal Agents (Prokinetic): Anticholinergic Agents may diminish the therapeutic effect of Gastrointestinal Agents (Prokinetic). Monitor therapy

Glucagon: Anticholinergic Agents may enhance the adverse/toxic effect of Glucagon. Specifically, the risk of gastrointestinal adverse effects may be increased. Monitor therapy

Glycopyrrolate (Oral Inhalation): Anticholinergic Agents may enhance the anticholinergic effect of Glycopyrrolate (Oral Inhalation). Avoid combination

Ipratropium (Oral Inhalation): May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Itopride: Anticholinergic Agents may diminish the therapeutic effect of Itopride. Monitor therapy

Levosulpiride: Anticholinergic Agents may diminish the therapeutic effect of Levosulpiride. Avoid combination

Mianserin: May enhance the anticholinergic effect of Anticholinergic Agents. Monitor therapy

Mirabegron: Anticholinergic Agents may enhance the adverse/toxic effect of Mirabegron. Monitor therapy

Nitroglycerin: Anticholinergic Agents may decrease the absorption of Nitroglycerin. Specifically, anticholinergic agents may decrease the dissolution of sublingual nitroglycerin tablets, possibly impairing or slowing nitroglycerin absorption. Monitor therapy

OnabotulinumtoxinA: Anticholinergic Agents may enhance the anticholinergic effect of OnabotulinumtoxinA. Monitor therapy

Opioid Analgesics: Anticholinergic Agents may enhance the adverse/toxic effect of Opioid Analgesics. Specifically, the risk for constipation and urinary retention may be increased with this combination. Monitor therapy

Oxatomide: May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Potassium Chloride: Anticholinergic Agents may enhance the ulcerogenic effect of Potassium Chloride. Management: Patients on drugs with substantial anticholinergic effects should avoid using any solid oral dosage form of potassium chloride. Avoid combination

Potassium Citrate: Anticholinergic Agents may enhance the ulcerogenic effect of Potassium Citrate. Avoid combination

Pramlintide: May enhance the anticholinergic effect of Anticholinergic Agents. These effects are specific to the GI tract. Consider therapy modification

Ramosetron: Anticholinergic Agents may enhance the constipating effect of Ramosetron. Monitor therapy

RimabotulinumtoxinB: Anticholinergic Agents may enhance the anticholinergic effect of RimabotulinumtoxinB. Monitor therapy

Secretin: Anticholinergic Agents may diminish the therapeutic effect of Secretin. Management: Avoid concomitant use of anticholinergic agents and secretin. Discontinue anticholinergic agents at least 5 half-lives prior to administration of secretin. Consider therapy modification

Thiazide and Thiazide-Like Diuretics: Anticholinergic Agents may increase the serum concentration of Thiazide and Thiazide-Like Diuretics. Monitor therapy

Tiotropium: Anticholinergic Agents may enhance the anticholinergic effect of Tiotropium. Avoid combination

Topiramate: Anticholinergic Agents may enhance the adverse/toxic effect of Topiramate. Monitor therapy

Umeclidinium: May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Adverse Reactions

Frequency not defined.

Cardiovascular: Hypotension (IV administration)

Central nervous system: Coma, depression, disorientation, dizziness, drowsiness, extrapyramidal reaction, headache, opisthotonos, Parkinsonian-like symptoms, seizure

Dermatologic: Allergic skin reaction

Gastrointestinal: Diarrhea

Hematologic & oncologic: Hematologic disease

Hepatic: Jaundice

Hypersensitivity: Hypersensitivity reaction

Local: Burning sensation at injection site, erythema at injection site, pain at injection site, swelling at injection site

Neuromuscular & skeletal: Muscle cramps

Ophthalmic: Blurred vision

Warnings/Precautions

Concerns related to adverse effects:

• CNS effects: CNS serious adverse effects (eg, coma, mood depression, disorientation, seizure) have been reported. Consider reducing the daily dosage by increasing the dosing interval or discontinuing use if serious CNS reactions occur. May cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks which require mental alertness (eg, operating machinery or driving). Recent or concomitant use of other medications causing CNS depression or adverse events may increase the risk of serious CNS reactions.

• Extrapyramidal symptoms: May cause extrapyramidal symptoms (EPS), primarily acute dystonic reactions (ie, sudden onset of muscular spasms usually in the head/neck or opisthotonos); other EPS (akathisia, restlessness, akinesia, other parkinsonian-like symptoms [eg, tremor]), laryngospasm, dysphagia, oculogyric crisis) may also occur. If EPS occurs, reduce the daily dosage by increasing the dosing interval or discontinue therapy, depending on the severity of symptoms. Treat acute dystonic reactions with anticholinergics. Avoid use in patients receiving concomitant therapy (eg, antipsychotics) that cause EPS.

• Hepatotoxicity: Use may potentially cause hepatotoxicity. If hepatic impairment occurs during therapy, discontinue use.

• Skin reactions: Allergic-type skin reactions have been reported with use; discontinue with signs of sensitization.

Disease-related concerns:

• Hepatic impairment: Avoid use in patients with hepatic impairment.

• Renal impairment: Use with caution in patients with renal impairment; clearance is predominantly renal; dosage reduction recommended in patients with CrCl ≤70 mL/minute/1.73 m2.

Concurrent drug therapy issues:

• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Special populations:

• Pediatric: Injection is contraindicated in children. Oral formulation is not recommended for use in pediatrics due to risk of EPS, serious CNS effects, and other potential adverse effects associated with use.

Other warnings/precautions:

• Masking effects: EPS and other CNS effects that may result from use may mask signs of an undiagnosed primary disease (eg, encephalopathy, metabolic imbalance, Reye syndrome). If CNS symptoms occur, evaluate the risks vs. benefits of continuing therapy.

Monitoring Parameters

Renal function

Pregnancy Considerations

Adverse events were observed in some animal reproduction studies. Although use for the treatment of nausea and vomiting in pregnancy has been reported (Pretorius 1961), use of other agents is recommended (ACOG 2015; Arsenault 2002).

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Patient may experience diarrhea, fatigue, or headache. Have patient report immediately to prescriber signs of liver problems (dark urine, fatigue, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or jaundice), severe dizziness, passing out, tremors, difficulty moving, rigidity, abnormal movements, muscle spasm, muscle cramps, difficulty swallowing, difficulty speaking, agitation, change in balance, severe loss of strength and energy, blurred vision, depression, seizures, confusion, chills, pharyngitis, bruising, or bleeding (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.

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