Tigan

Tigan,

trademark for an antiemetic (trimethobenzamide hydrochloride).

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trimethobenzamide hydrochloride

Tigan

Pharmacologic class: Anticholinergic

Therapeutic class: Antiemetic

Pregnancy risk category C

Action

Unclear. Thought to block dopamine receptors and emetic impulses in chemoreceptor trigger zone, preventing nausea and vomiting.

Availability

Capsules: 100 mg, 250 mg, 300 mg

Injection: 100 mg/ml in 2-ml ampules and prefilled syringes and in 20-ml vials

⊘Indications and dosages

➣ Nausea and vomiting

Adults: 250 mg P.O. three to four times daily or 200 mg I.M. three to four times daily

Children weighing 13.6 to 40.8 kg (30 to 90 lb): 100 to 200 mg P.O. three to four times daily

Contraindications

• Hypersensitivity to drug
• Parenteral form in children

Precautions

Use cautiously in:
• arrhythmias, encephalitis, gastroenteritis, dehydration, electrolyte imbalances
• elderly or debilitated patients
• pregnant or breastfeeding patients
• children with known or suspected viral illnesses.

Administration

• In I.M. use, inject deep into upper outer quadrant of gluteus maximus.
• Withhold drug in children with signs or symptoms of Reye's syndrome.

Route	Onset	Peak	Duration
P.O.	10-40 min	Unknown	3-4 hr
I.M.	15-35 min	Unknown	2-3 hr

Adverse reactions

CNS: drowsiness, dizziness, headache, depression, disorientation, parkinsonian symptoms, coma, seizures

CV: hypotension

EENT: blurred vision

Hematologic: blood dyscrasias

Hepatic: jaundice

Musculoskeletal: muscle cramps, opisthotonos

Skin: rash, urticaria, flushing

Other: pain and stinging at I.M. injection site, hypersensitivity reaction

Interactions

Drug-drug. Antidepressants, antihistamines, CNS depressants, opioids, sedative-hypnotics: additive CNS depression

Drug-behaviors. Alcohol use: additive CNS depression

Patient monitoring

• Monitor neurologic status, especially for parkinsonian symptoms and other serious adverse reactions.
• Assess CBC and liver function tests. Watch for blood dyscrasias and jaundice.
• Evaluate injection site for pain and stinging.
• Closely monitor patient's nutritional and hydration status. Report continuing nausea.

Patient teaching

• Advise patient to take as needed for nausea and vomiting, but only as prescribed.
• Tell patient to contact prescriber promptly if nausea persists despite therapy.
• Instruct patient to minimize nausea and vomiting by eating small, frequent servings of healthy food and drinking plenty of fluids.
• Advise patient to avoid alcohol.
• Caution patient to avoid driving and other hazardous activities until drug effects are known.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and behaviors mentioned above.