trimethobenzamide

Therapeutic Classification: antiemetics

Pharmacologic Classification: anticholinergics

Indications ⬆ ⬇

REMS

Mild to moderate nausea and vomiting.

Action ⬆ ⬇

Inhibits emetic stimulation of the chemoreceptor trigger zone in the medulla.

Therapeutic effects:

Decreased nausea and vomiting.

Pharmacokinetics ⬆ ⬇

Absorption: Complete absorption following oral and IM administration.

Distribution: Unknown.

Metabolism/Excretion: Metabolized by the liver; 30–50% excreted unchanged in urine.

Half-Life: 7–9 hr.

Time/Action Profile ⬆ ⬇

(antiemetic effect)

ROUTE	ONSET	PEAK	DURATION
PO	10–40 min	unknown	3–4 hr
IM	15–35 min	unknown	2–3 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity.

Use Cautiously in:

OB: Safety not established in pregnancy;
Lactation: Safety not established in breastfeeding;
Pedi: Safety and effectiveness not established in children;
Geri: risk of adverse reactions in older adults secondary to age-related in renal function.

Adv. Reactions/Side Effects ⬆ ⬇

CV: hypotension

GI: diarrhea, hepatitis

Derm: rash

Hemat: blood dyscrasias

Local: pain at injection site, burning/redness/stinging at IM injection site

Neuro: drowsiness, COMA, depression, extrapyramidal reactions, SEIZURES

Interactions ⬆ ⬇

Drug-drug:

↑CNS depression with other CNS depressants, including alcohol, antidepressants, antihistamines, opioid analgesics, and sedative/hypnotics.

Route/Dosage ⬆ ⬇

PO (Adults ): 300 mg 4 times daily.
IM (Adults ): 200 mg 3–4 times daily as needed.

Renal Impairment

(Adults ): CCr ≤70 mL/min: ↓dose or ↑ dosing interval.

Availability ⬆ ⬇

(Generic available)

Capsules: 300 mg
Solution for injection: 100 mg/mL

Assessment ⬆ ⬇

Assess patient for nausea and vomiting prior to and 30–60 min following administration.
Assess BP for hypotension following parenteral administration.

Implementation ⬆ ⬇

PO: Capsules can be opened and contents mixed with food or fluids for patients with difficulty swallowing.
IM: Inject deep into well-developed muscle mass to minimize tissue irritation.
- Trimethobenzamide is not recommended for IV use.

Patient/Family Teaching ⬆ ⬇

Instruct patient to take medication as directed. Take missed doses as soon as remembered unless almost time for next dose; do not double doses.
Advise patient to make position changes slowly to minimize orthostatic hypotension following parenteral doses.
May cause drowsiness. Caution patient to avoid driving or other activities requiring alertness until response to medication is known.
Caution patient to avoid taking alcohol or other CNS depressants concurrently with this medication.
Instruct patient to notify health care professional promptly if sore throat, fever, unusual weakness or tiredness, tremors, or yellowing of the skin and eyes occurs.
Rep: Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding.

section name header

Pronunciation ⬇

Classifications ⬆ ⬇