Tigan


Tigan

 [ti´gan] trademark for preparations of trimethobenzamide hydrochloride, an antiemetic.

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

Dosage adjustment

• Renal impairment

Contraindications

• Hypersensitivity to drug

• Parenteral form in children

Precautions

Use cautiously in:

• renal impairment, arrhythmias, encephalitis, gastroenteritis, dehydration, electrolyte imbalances

• concurrent alcohol use

• 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.

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.

trimethobenzamide

(trye-meth-oh-ben-za-mide) trimethobenzamide,

Tigan

(trade name)

Classification

Therapeutic: antiemetics
Pharmacologic: anticholinergics
Pregnancy Category: C

Indications

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 and Excretion: Metabolized by the liver; 30–50% excreted unchanged in urine.Half-life: 7–9 hr.

Time/action profile (antiemetic effect)

ROUTEONSETPEAKDURATION
PO10–40 minunknown3–4 hr
IM15–35 minunknown2–3 hr

Contraindications/Precautions

Contraindicated in: Hypersensitivity.Use Cautiously in: Pediatric: Children; Geriatric: Appears on Beers list. Potential for extrapyramidal side effects may outweigh potential benefit; Obstetric / Lactation: Safety not established.

Adverse Reactions/Side Effects

Central nervous system

  • coma (life-threatening)
  • seizures (life-threatening)
  • drowsiness (most frequent)
  • depression
  • extrapyramidal reactions

Cardiovascular

  • hypotension (most frequent)

Gastrointestinal

  • diarrhea
  • hepatitis

Dermatologic

  • rashes

Hematologic

  • blood dyscrasias

Local

  • pain (most frequent)
  • burning at IM injection site
  • redness at IM injection site
  • stinging at IM injection site

Interactions

Drug-Drug interaction

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

Route/Dosage

Oral (Adults) 300 mg 3–4 times daily.Intramuscular (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 Injection: 100 mg/mL

Nursing implications

Nursing assessment

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

Potential Nursing Diagnoses

Risk for deficient fluid volume (Indications)
Risk for injury (Side Effects)

Implementation

  • Oral: Capsules can be opened and contents mixed with food or fluids for patients with difficulty swallowing.
  • Intramuscular: Inject deep into well-developed muscle mass to minimize tissue irritation.
    • Trimethobenzamide is not receommended 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.

Evaluation/Desired Outcomes

  • Prevention and relief of nausea and vomiting.