Dosing and uses of Bontril, Bontril PDM (phendimetrazine)
Adult dosage forms and strengths
capsules, extended release: Schedule III
- 105mg
tablet: Schedule III
- 35mg
Obesity
Tablet: 35 mg q8-12hr 1 hr AC
Range: 17.5 mg q12hr to 70 mg q8hr; not to exceed 70 mg PO q8hr
Extended release capsule: 105 mg qAm
Pediatric dosage forms and strengths
Because pediatric obesity is a chronic condition requiring long-term treatment, the use of amphetamines approved for short-term therapy is not recommended in patients <17 years of age
Bontril, Bontril PDM (phendimetrazine) adverse (side) effects
Frequency not defined
Abnormal heart valve findings
Agitation
Blurred vision
Changes in libido
Constipation
Diarrhea
Dizziness
Dryness of the mouth
Dysphoria
Dysuria
Euphoria
Flushing
Headache
Impotence
Increased Bp
Insomnia
Nausea
Palpitation
Primary pulmonary HTn
Stomach pain
Sweating
Tachycardia
Tremor
Unpleasant taste
Urticaria
Warnings
Contraindications
Hypersensitivity
History of cardiovascular disease (eg, coronary artery disease, stroke, arrhythmias, congestive heart failure, uncontrolled hypertension, pulmonary hypertension)
Hyperthyroidism
Glaucoma
Agitated states
History of drug abuse
Pregnancy
Breast feeding
Coadministration with other anorectic agents or CNS stimulants
Do not administer within 14 days of administration of MAO inhibitors
Cautions
Impairs ability to drive or operate heavy machinery
Primary pulmonary hypertension associated with treatment
Use with other anorectic agents
Possibility of addiction
Caution advised; increased exposure expected when administered to patients with renal impairment; excreted in urine
Pregnancy and lactation
Pregnancy category: X; weight loss offers no potential benefit to a pregnant woman and may result in fetal harm; a minimum weight gain, and no weight loss, is currently recommended for all pregnant women, including those who are already overweight or obese
Lactation: Contraindicated; do not nurse if taking this drug
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Bontril, Bontril PDM (phendimetrazine)
Mechanism of action
Anorectic; sympathomimetic amine similar to amphetmine; may act in CNS to reduce appetite
Pharmacokinetics
Metabolism: Forms 2 metabolites
Metabolites: Phendimetrazine-N-oxide
Absorption: readily absorbed from GI tract
Duration: 4 hr
Excretion: Urine
Half-life: 1.9 hr (tablet); 9.8 hr (slow release)
