Nervagest Plus Drug Interactions

Pregabalin, at concentrations that were, in general, 10-times those attained in clinical trials, does not inhibit human CYP1A2, CYP2A6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4 enzyme systems. In vitro drug interaction studies demonstrate that pregabalin does not induce CYP1A2 or CYP3A4 activity. Therefore, an increase in the metabolism of co-administered CYP1A2 substrates (e.g. theophylline, caffeine) or CYP3A4 substrates (e.g. midazolam, testosterone) is not anticipated.
The drug interaction studies described below were conducted in healthy adults, and across various patient populations.
Gabapentin: Gabapentin pharmacokinetics following single- and multiple-dose administration was unaltered by pregabalin co-administration. The extent of pregabalin absorption was unaffected by gabapentin co-administration, although there was a small reduction in rate of absorption.
Oral Contraceptive: Pregabalin co administration (200 mg three times a day) had no effect on the steady-state pharmacokinetics of norethindrone and ethinyl estradiol (1 mg/35 μg, respectively) in healthy subjects.
Lorazepam: Multiple-dose administration of pregabalin (300 mg twice a day) in healthy subjects had no effect on the rate and extent of lorazepam single-dose pharmacokinetics and single-dose administration of lorazepam (1 mg) had no effect on the steady-state pharmacokinetics of pregabalin.
Oxycodone: Multiple-dose administration of pregabalin (300 mg twice a day) in healthy subjects had no effect on the rate and extent of oxycodone single-dose pharmacokinetics. Single-dose administration of oxycodone (10 mg) had no effect on the steady-state pharmacokinetics of pregabalin.
Ethanol: Multiple-dose administration of pregabalin (300 mg twice a day) in healthy subjects had no effect on the rate and extent of ethanol single-dose pharmacokinetics and single-dose administration of ethanol (0.7 g/kg) had no effect on the steady-state pharmacokinetics of pregabalin.
Antiepileptic Drugs: Steady-state trough plasma concentrations of phenytoin, phenobarbital, topiramate, carbamazepine and carbamazepine 10, 11 epoxide, valproic acid, and lamotrigine were not affected by concomitant pregabalin (200 mg three times a day) administration. These drugs have no effect on the pharmacokinetics of pregabalin and pregabalin has no effect on the pharmacokinetics of the mentioned drugs. Tiagabine also had no effect the pharmacokinetics of pregabalin.
As with all AEDs, pregabalin should be withdrawn gradually to minimize the potential of increased seizure frequency in patients with seizure disorders. If pregabalin is discontinued this should be done gradually over a minimum of 1 week.
Oral hypoglycemic: Concomitant administration of glyburide, insulin or metformin with pregabalin did not affect the pharmacokinetics of pregabalin.
Furosemide: Concomitant administration of furosemide with pregabalin did not affect the pharmacokinetics of pregabalin.
CNS Depressants: Patients who require concomitant treatment with CNS depressants such as opiates or benzodiazepines should be informed that they may experience additive CNS side effects, such as somnolence.
Alcohol: Patients should be told to avoid consuming alcohol while taking pregabalin, as pregabalin may potentiate the impairment of motor skills and sedating effects of alcohol.
Antibiotics: May alter the intestinal microflora and may decrease the absorption of methylcobalamin.
Cholestyramine, colchicines or colestipol: May decrease the enterohepatic re-absorption of methylcobalamin.
Metformin, para-aminosalicylic acid and potassium chloride: May decrease the absorption of methylcobalamin.
Nitrous oxide: Can produce a functional methylcobalamin deficiency.
Patient with Renal impairment: Pregabalin dosage adjustment should be considered in cases of renal impairment. (Refer to Dosage & Administration, Patients with renal impairment).
Drug Interactions: Absorption of vitamin B12 from the gastrointestinal tract may be reduced by neomycin, aminosalicylic acid, histamine H2-antagonists, omeprazole and colchicine. Serum concentrations may be decreased by use of oral contraceptives. Many of these interactions are unlikely to be of clinical significance but should be taken into account when performing assays for blood concentrations. Parenteral chloramphenicol may attenuate the effect of vitamin B12 in anemia.