trimipramine (Surmontil)

Introduction

Tradename: Surmontil.

Indications

• treatment of depression
• neuralgia

Contraindications

• angle-closure glaucoma
• recovery phase of acute myocardial infarction
• avoid use during lactation

Caution:

• cardiovascular disease
• conduction disturbances
• seizure disorder
• urinary retention
• hyperthyroidism
• concurrent administration of thyroid replacement
• concurrent MAO inhibitor therapy
• use with caution during pregnancy

pregnancy category = c

safety in lactation = ?

Dosage

• start 25-75 mg PO QHS
• usual effective dose is 50-150 mg PO QHS
• max 200 mg/day (outpatient); 300 mg/day (inpatient)
• taper when discontinuing large doses

Tabs: 25, 50, 100 mg.

Pharmacokinetics

• maximum antidepressant effects usually occur after more than 2 weeks of therapy

elimination via liver

1/2life = 16-40 hours

protein binding = 93-97 %

elimination by hemodialysis = -

elimination by hemodialysis = -

Adverse effects

• common (> 10%)
  • dizziness, drowsiness, headache, xerostomia, constipation, increased appetite, nausea, unpleasant taste, weight gain, weakness
• less common (1-10%)
  • arrhythmias, hypotension, confusion, delirium, hallucinations, nervousness, restlessness, parkinsonism, insomnia, sexual dysfunction, diarrhea, heartburn, dysuria, fine muscle tremors, blurred vision, eye pain, diaphoresis
• uncommon (< 1%)
  • anxiety, seizures, alopecia, photosensitivity, breast enlargement, galactorrhea, SIADH, gum disorder, decreased tone of lower esophageal sphincter, GERD, testicular edema, agranulocytosis, leukopenia, eosinophilia, cholestatic jaundice, hepatotoxicity, increased intraocular pressure, tinnitus, allergic reactions
• other
  • hyperglycemia
  • photosensitivity
  • blue-green discoloration of urine

• drug adverse effects of tricyclic antidepressants
• drug adverse effects of antidepressants
• drug adverse effects of psychotropic agents

Drug interactions

• coadministration enhances metabolism of trimipramine
  • barbiturates
  • carbamazepine
  • smoking
• coadministration inhibits metabolism of trimipramine
  • fluoxetine
  • methylphenidate
  • oral contraceptives
  • haloperidol
  • cimetidine
  • chloramphenicol
  • phenothiazines
• decreased effect of:
  • guanethidine, clonidine
• decreased effect with:
  • barbiturates, carbamazepine, phenytoin
• increased effect/toxicity with:
  • MAO inhibitors (hyperpyretic crises), CNS depressants, alcohol, methylphenidate (increased levels), cimetidine (decreased clearance), anticholinergics

• drug interaction(s) of tricyclic antidepressants with physostigmine
• drug interaction(s) of antidepressant in combination with GLP1-agonist
• drug interaction(s) of benzodiazepines with antidepressants
• drug interaction(s) of antidepressants with benzodiazepines
• drug interaction(s) of NSAIDs with antidepressants
• drug interaction(s) of antidepressant with opiates

Laboratory

• specimen:
  • serum, plasma (EDTA)
  • collect at steady state trough; > 12 hours after dose
  • stable for 5 months at -20 degrees C
• methods: GC, HPLC
• test interactions: trimipramine may increase serum glucose

More general terms

• tricyclic antidepressant (TCA)

Database

• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=5584
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=114766
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=5282318