Table 1.

Main contraindications, drug interactions, common adverse effects and stopping rules of liraglutide, lorcaserin, phentermine/topiramate and naltrexone/bupropion

Drug name	Contraindications	Drug interactions	Common adverse effects	Stopping rule
Liraglutide	It is unknown whether liraglutide causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans, as the human relevance of liraglutide-induced rodent thyroid C-cell tumors has not been determined. Also it is contraindicated in patients with a personal or family history of MTC or in patients with Multiple endocrine neoplasia syndrome type 2. Pregnant women or women who are nursing	Concurrent oral drug requiring rapid onset (it can delay gastric emptying)	Nausea, hypoglycemia [serious hypoglycemia can only occur when liraglutide is used with an insulin secretagogue (e.g. a sulfonylurea)], diarrhea, constipation, vomiting, headache, decreased appetite, dyspepsia, fatigue, dizziness, abdominal pain, and increased lipase	Stop if <4% weight loss at 16 weeks
Lorcaserin	Pregnant women, or women who are nursing	Based on the mechanism of action of lorcaserin and the theoretical potential for serotonin syndrome, use with extreme caution in combination with other drugs that may affect the serotonergic neurotransmitter systems, including, but not limited to, triptans, monoamine oxidase inhibitors (MAOIs, including linezolid, an antibiotic which is a reversible nonselective MAOI), selective serotonin reuptake inhibitors (SSRIs), selective serotonin-norepinephrine reuptake inhibitors (SNRIs), dextromethorphan, tricyclic antidepressants (TCAs), bupropion, lithium, tramadol, tryptophan, and St. John’s Wort	In patients without diabetes: headache (17%), dizziness (9%), fatigue (7%), nausea (8%), dry mouth (5%), and constipation (6%). In patients with diabetes: hypoglycemia (29%), headache (15%), back pain (12%), cough (8%), and fatigue (7%)	Stop if <5% loss at 12 weeks
Phentermine/topiramate CR	Pregnancy (teratogenic risk), glaucoma, hyperthyroidism, during or within 14 days of taking MAOIs, known hypersensitivity or idiosyncrasy to sympathomimetic amines. Should not be used by nursing mothers	Oral contraceptives: altered exposure may cause irregular bleeding but not increased risk of pregnancy; CNS depressants including alcohol: potentiate CNS depressant effects. Non-potassium sparing diuretics: may potentiate hypokalemia. Antiepileptic drugs: concomitant administration of phenytoin or carbamazepine with topiramate in patients with epilepsy, decreased plasma concentrations of topiramate by 48 and 40%, respectively, when compared to topiramate given alone. Concomitant administration of valproic acid and topiramate has been associated with hyperammonemia (with and without encephalopathy) and hypothermia (with and without hyperammonemia)	Paresthesias, dizziness, taste alterations, insomnia, constipation, dry mouth, elevation in heart rate, memory and cognitive changes, secondary acute angle closure glaucoma, suicidal behavior and ideation, fetal toxicity, mood and sleep changes, metabolic acidosis	If 3% weight loss is not achieved with 7.5 mg/46 mg dose after 12 weeks, stop or increase to 11.25 mg/69 mg for 14 days, then 15 mg/92 mg; Stop if <5% loss at 12 weeks on top dose
Naltrexone/bupropion	Uncontrolled hypertension; seizure disorders, anorexia nervosa or bulimia, or undergoing abrupt discontinuation of alcohol, benzodiazepines, barbiturates, and antiepileptic drugs; use of other bupropion-containing products; chronic opioid use; during or within 14 days of taking MAOIs; pregnant women or women who are nursing	MAOIs: Increased risk of hypertensive reactions can occur when used concomitantly. Bupropion inhibits CYP2D6 and can increase concentrations of: antidepressants, (e.g., selective serotonin reuptake inhibitors and many tricyclics), antipsychotics (e.g., haloperidol, risperidone and thioridazine), beta-blockers (e.g., metoprolol) and Type 1C antiarrhythmics (e.g., propafenone and flecainide). Concomitant treatment with CYP2B6 Inhibitors (e.g., ticlopidine or clopidogrel) can increase bupropion exposure. Do not exceed one tablet twice daily when taken with CYP2B6 inhibitors. CYP2B6 Inducers (e.g., ritonavir, lopinavir, efavirenz, carbamazepine, phenobarbital, and phenytoin) may reduce efficacy by reducing bupropion exposure, avoid concomitant use. Dopaminergic drugs (levodopa and amantadine): CNS toxicity can occur when used concomitantly with natrexone/buprobion combination. Drug-laboratory test interactions: natrexone/buprobion can cause false-positive urine test results for amphetamines	Constipation, headache, nausea, vomiting, dizziness, insomnia, dry mouth and diarrhea	Stop if <5% loss at 12 weeks