SIBUTRAMINE HYDROCHLORIDE MONOHYDRATE

Medical Diagnosis and Drugs, Medications

SIBUTRAMINE HYDROCHLORIDE MONOHYDRATE
(si-bu'tra-meen)
Meridia
Classifications: cns stimulant, anorexiant;
Therapeutic:appetite suppressant
Pregnancy Category: C
Controlled Substance: Schedule IV

Availability

5 mg, 10 mg, 15 mg capsules

Action

Inhibits central reuptake of serotonin (5-HT₃), monoamine reuptake, as well as norepinephrine and dopamine reuptake, by blocking their receptors.

Therapeutic Effect

Appetite suppression by enhancing satiety and raising the metabolic rate. Indicated by a loss of at least 4 lb during the first 4 wk of therapy.

Uses

Management of obesity, including weight loss and maintenance of weight loss, in patients with BMI of at least 30 kg/m² or BMI of at least 27 kg/m² and other risk factors (hypertension, diabetes, dyslipidemia).

Contraindications

Major eating disorders; anorexia nervosa, bulimia; arrhythmias; concurrent administration with other serotonin reuptake inhibitors (e.g., fluoxetine), MAOIs, lithium, tryptophan; severe hepatic or renal impairment; ESRD, dialysis; CHF, stroke, CAD; uncontrolled or poorly controlled hypertension; seizures; pregnancy (category C), lactation.

Cautious Use

History of hypertension; older adults; narrow-angle glaucoma; mild or moderate hepatic disease; renal impairment. Safety and efficacy in patients <16 y are not established.

Route & Dosage

Weight Loss
Adult: PO 10 mg once daily, preferably in morning, may be increased to 15 mg if inadequate weight loss (<4 lb) in 4 wk

Administration

Oral

Note: Doses above 15 mg/d are not recommended.
Allow at least 2 wk to elapse between discontinuing an MAOI and starting sibutramine.
Store at 15°–30° C (59°–86° F) in a tightly closed container; protect from light.

Adverse Effects (≥1%)

Body as a Whole: Back pain, flu-like syndrome, asthenia, arthralgia. CNS: Headache, insomnia, migraine headache, dizziness, nervousness, anxiety, depression, paresthesias, seizures (rare). CV: Increase in BP, tachycardia, vasodilation, palpitations. GI: Dry mouth, anorexia, constipation, abdominal pain, increased appetite, nausea, dyspepsia, taste perversion. Respiratory: Rhinitis, pharyngitis, sinusitis, cough. Skin: Rash, sweating. Urogenital: Dysmenorrhea, UTI.

Interactions

Drug: decongestants, cough and allergy medications may cause additional increase in BP; maois, ergot derivatives, sumatriptan, naratriptan, rizatriptan, zolmitriptan, dextromethorphan, meperidine, pentazocine, fentanyl, lithium; ssris may predispose to serotonin syndrome (see Appendix F); ketoconazole, erythromycin may inhibit metabolism of sibutramine. Herbal: St. John's wort may cause serotonin syndrome (headache, dizziness, sweating, agitation).

Pharmacokinetics

Absorption: Rapidly from GI tract. Peak: 1.2 h. Distribution: 97% protein bound; concentrates in liver and kidneys. Metabolism: In liver by cytochrome P450 3A4 to 2 active metabolites. Elimination: Primarily in kidneys. Half-Life: 14–16 h (active metabolites).

Nursing Implications

Assessment & Drug Effects

Monitor weight changes carefully to determine therapeutic effect.
Lab tests: Periodic liver function, bilirubin, alkaline phosphatases, lipid profile.
Monitor BR and HR regularly; report sustained increases in BP or HR immediately.
Monitor for and immediately report S&S of serotonin syndrome (see Appendix F).
Monitor persons with narrow-angle glaucoma closely for worsening intraocular pressure.

Patient & Family Education

Notify physician if any of the following develop: Rash, hives, or other S&S of an allergic reaction; signs of hyperstimulation such as restlessness, shivering, profuse sweating, irritability, and tremor.
Take in the morning; causes less interference with sleep.
Check with physician before taking any OTC cough, cold, allergy, or weight-loss drugs.
Maintain strict adherence to prescribed antihypertensives.
Inform physician of all drugs being taken. Serious adverse effects may be experienced with concomitant use of some drugs used to treat depression.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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