Pregabalin (3 brand names, 3 dosage forms, 1 route)
Available dosage forms: CAPSULE, TABLET, EXTENDED RELEASE, SOLUTION.
Routes of administration: ORAL.
Brand Names
- LYRICA
- LYRICA CR
- PREGABALIN
Indications and Usage
Pregabalin capsules are indicated for: Management of neuropathic pain associated with diabetic peripheral neuropathy Management of postherpetic neuralgia Adjunctive therapy for the treatment of partial-onset seizures in patients 1 month of age and older Management of fibromyalgia Management of neuropathic pain associated with spinal cord injury
Contraindications
Pregabalin capsules are contraindicated in patients with known hypersensitivity to pregabalin or any of its components. Angioedema and hypersensitivity reactions have occurred in patients receiving pregabalin therapy [see Warnings and Precautions (5.2)].
Adverse Reactions
The following serious adverse reactions are described elsewhere in the labeling: Angioedema [see Warnings and Precautions (5.1)] Hypersensitivity [see Warnings and Precautions (5.2)] Suicidal Behavior and Ideation [see Warnings and Precautions (5.3)] Increased Risk of Adverse Reactions with Abrupt or Rapid Discontinuation [see Warnings and Precautions (5.4)] Respiratory Depression [see Warnings and Precautions (5.5)] Dizziness and Somnolence [see Warnings and Precautions (5.6) ] Peripheral Edema [see Warnings and Precautions (5. 7) ] Weight Gain [see Warnings and Precautions (5.8)] Tumorigenic Potential [see Warnings and Precautions (5.9)] Ophthalmological Effects [see Warnings and Precautions (5.10)] Creatine Kinase Elevations [see Warnings and Precautions (5.11)] Decreased Platelet Count [see Warnings and Precautions (5.12)] PR Interval Prolongation [see Warnings and Precautions (5.13)]
Drug Interactions
Since pregabalin is predominantly excreted unchanged in the urine, undergoes negligible metabolism in humans (less than 2% of a dose recovered in urine as metabolites), and does not bind to plasma proteins, its pharmacokinetics are unlikely to be affected by other agents through metabolic interactions or protein binding displacement. In vitro and in vivo studies showed that pregabalin is unlikely to be involved in significant pharmacokinetic drug interactions. Specifically, there are no pharmacokinetic interactions between pregabalin and the following antiepileptic drugs: carbamazepine, valproic acid, lamotrigine, phenytoin, phenobarbital, and topiramate. Important pharmacokinetic interactions would also not be expected to occur between pregabalin and commonly used antiepileptic drugs [see Clinical Pharmacology (12)]. Pharmacodynamics Multiple oral doses of pregabalin were co-administered with oxycodone, lorazepam, or ethanol. Although no pharmacokinetic interactions were seen, additive effects on cognitive and gross motor functioning were seen when pregabalin was co-administered with these drugs. No clinically important effects on respiration were seen.
Mechanism of Action
Pregabalin binds with high affinity to the alpha2-delta site (an auxiliary subunit of voltage-gated calcium channels) in central nervous system tissues. Although the mechanism of action of pregabalin has not been fully elucidated, results with genetically modified mice and with compounds structurally related to pregabalin (such as gabapentin) suggest that binding to the alpha2-delta subunit may be involved in pregabalin’s anti-nociceptive and antiseizure effects in animals. In animal models of nerve damage, pregabalin has been shown to reduce calcium-dependent release of pro-nociceptive neurotransmitters in the spinal cord, possibly by disrupting alpha2-delta containing-calcium channel trafficking and/or reducing calcium currents. Evidence from other animal models of nerve damage and persistent pain suggest the anti-nociceptive activities of pregabalin may also be mediated through interactions with descending noradrenergic and serotonergic pathways originating from the brainstem that modulate pain transmission in the spinal cord. While pregabalin is a structural derivative of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA), it does not bind directly to GABAA, GABAB, or benzodiazepine receptors, does not augment GABAA responses in cultured neurons, does not alter rat brain GABA concentration or have acute effects on GABA uptake or degradation. However, in cultured neurons prolonged application of pregabalin increases the density of GABA transporter protein and increases the rate of functional GABA transport. Pregabalin does not block sodium channels, is not active at opiate receptors, and does not alter cyclooxygenase enzyme activity. It is inactive at serotonin and dopamine receptors and does not inhibit dopamine, serotonin, or noradrenaline reuptake.
Overdosage
Signs, Symptoms and Laboratory Findings of Acute Overdosage in Humans In the post-marketing experience, the most commonly reported adverse events observed with pregabalin when taken in overdose include reduced consciousness, depression/anxiety, confusional state, agitation, and restlessness. Seizures and heart block have also been reported. Deaths have been reported in the setting of lone pregabalin overdose and in combination with other CNS depressants. Treatment or Management of Overdose There is no specific antidote for overdose with pregabalin. If indicated, elimination of unabsorbed drug may be attempted by emesis or gastric lavage; observe usual precautions to maintain the airway. General supportive care of the patient is indicated including monitoring of vital signs and observation of the clinical status of the patient. Contact a Certified Poison Control Center for up-to-date information on the management of overdose with pregabalin. Pregabalin can be removed by hemodialysis. Standard hemodialysis procedures result in significant clearance of pregabalin (approximately 50% in 4 hours).