PHARMACOLOGY

Pharmacotherapeutic Group: Anti-convulsant

Pharmacodynamic Properties: Pregabalin is an anticonvulsant drug which binds to the α₂δ (alpha₂ delta) subunit of the voltage-dependent calcium channel in the central nervous system. This reduces calcium influx into the nerve terminals. Pregabalin also decreases the release of neurotransmitters such as glutamate, noradrenaline and substance P, possibly accounting for its actions in vivo to reduce neuronal excitability and seizures Pregabalin increases neuronal GABA levels by producing a dose-dependent increase in glutamic acid decarboxylase activity.

 Pharmacokinetic Properties:

Absorption: Rapidly absorbed after oral doses. Peak plasma concentrations are achieved within 1.5 hours. Bioavailability: >90%

Distribution:Not bound to plasma proteins.

Metabolism:Negligible metabolism.

Elimination:About 98% excreted unchanged in urine. Elimination half life: about 6.3 hours.

 INDICATIONS

Diabetic peripheral neuropathy, postherpetic neuralgia, adjunct in partial seizures, fibromyalgia, anxiety, neuropathic pain associated with spinal cord injury, trigeminal neuralgia

DOSE

Diabetic peripheral neuropathy: Adult: 50 mg tid or 75 mg bid. Max. dose: 100mg tid.

Postherpetic neuralgia: Adult: 75-150 mg bid. May increase up to 600 mg/day in patients with ongoing pain and can tolerate 300 mg/day.

Adjunct in partial seizures: Adult: 150-600 mg/day. Should be given in 2-3 divided doses. Max dose: 600 mg/day

Fibromyalgia: Adult: Initiate at 75 mg bid. May increase to 225 mg bid for patients who do not experience sufficient benefit with 300 mg/day.

Anxiety: Adult: Initiate at 150 mg daily. May increase at weekly intervals in steps of 150 mg. Max dose: 600 mg daily.

Neuropathic pain with spinal cord injury: 75mg bid.

CONTRAINDICATIONS

Hypersensitivity

 SPECIAL PRECAUTIONS

Discontinue treatment if patients develop severe angioedema. Withdraw treatment gradually over at least 1 week. May cause peripheral edema. Regular vision check is recommended. May decrease platelet count and prolong PR interval.

ADVERSE DRUG REACTIONS

Dizziness, drowsiness, visual disturbance (including blurred vision, diplopia), rash, muscle cramp, myalgia, arthralgia.

 DRUG INTERACTIONS

Concurrent use with oxycodone, lorazepam and ethanol may increase the CNS effects.

 PRESENTATION

Each box is supplied with 10 strips of 10 caps packed in blisters.