Pregmax M-75

Pregabalin and mecobalamin.

Each capsule contains: Pregabalin 75 mg and mecobalamin 750 mcg.

Pharmacology: Pharmacokinetics: Pregabalin is rapidly absorbed after oral doses and peak plasma concentrations are achieved within 1.5 hrs. Oral bioavailability is about 90%. The rate but not the extent of absorption is reduced if given with food but this is not clinically significant. Steady-state is achieved after 1-2 days. Pregabalin is not bound to plasma proteins and undergoes negligible metabolism. About 98% of a dose is excreted in the urine as unchanged drug. The mean elimination half-life is 6.3 hrs. Pregabalin is removed by hemodialysis.
Mecobalamin substances bind to intrinsic factor, a glycoprotein secreted by the gastric mucosa, and are then actively absorbed from the gastrointestinal tract. Absorption is impaired in patients with an absence of intrinsic factor, with a malabsorption syndrome or with disease or abnormality of the gut, or after gastrectomy. Absorption from the gastrointestinal tract can also occur by passive diffusion; little of the vitamin present in food is absorbed in this manner although the process becomes increasingly important with larger amounts eg, those used therapeutically. After intranasal dosage, peak plasma concentrations of cyanocobalamin have been reached in 1-2 hrs. The bioavailability of the intranasal preparation is about 7-11% of that by IM injection.
Vitamin B₁₂ is extensively bound to specific plasma proteins called transcobalamins; transcobalamin II appears to be involved in the rapid transport of the cobalamins into tissues. Vitamin B₁₂ is stored in the liver, excreted in the bile and undergoes extensive enterohepatic recycling; part of a dose is excreted in the urine, most of it in the first 8 hrs; urinary excretion, however, accounts for only a small fraction in the reduction of total body stores acquired by dietary means. Vitamin B₁₂ diffuses across the placenta and also appears in breast milk.

Indicated in the management of peripheral neuropathy.

Starting Dose: 1 cap twice daily; provided this is tolerable vis-a-vis renal function. Patients previously on gabapentin will have a wash-out period of 1 week prior to start of dosing with pregabalin.

Mecobalamin: Allergic hypersensitivity reactions have occurred rarely after parenteral doses of the vitamin B₁₂ compounds, cyanocobalamin and hydroxocobalamin. Antibodies to hydroxocobalamin-transcobalamin II complex have developed during hydroxocobalamin therapy. Arrhythmias secondary to hypokalemia have occurred at the beginning of parenteral treatment with hydroxocobalamin. Intranasal cyanocobalamin may cause rhinitis, nausea and headache.
Cyanocobalamin or hydroxocobalamin should, if possible, not be given to patients with suspected vitamin B₁₂ deficiency without 1st confirming the diagnosis. Regular monitoring of the blood is advisable. Use of doses >10 mcg daily may produce a hematological response in patients with folate deficiency; indiscriminate use may mask the precise diagnosis. Conversely, folate may mask vitamin B₁₂ deficiency. Cyanocobalamin should not be used for Leber's disease or tobacco amblyopia since these optic neuropathies may degenerate further.
Pregabalin: The most common adverse effects reported during therapy with pregabalin are dizziness and somnolence. Other common adverse effects include blurred vision, diplopia, increased appetite and weight gain, dry mouth, constipation, vomiting, flatulence, euphoria, confusion, reduced libido, erectile dysfunction, irritability, vertigo, ataxia, tremor, dysarthria, paraesthesia, fatigue and edema. Disturbances of attention, memory, coordination and gait also occur frequently. Syncope and congestive heart failure have been reported less frequently. Reversible renal failure, elevation of creatine kinase concentration and rhabdomyolysis have been reported rarely. Hypersensitivity reactions have occurred shortly after starting pregabalin therapy; symptoms include rash, blisters, urticaria, dyspnea and wheezing. Stevens-Johnson syndrome has also been reported. An increased incidence of hemangiosarcoma was observed in mice that had been given high doses of pregabalin.

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.

Store at temperatures not exceeding 30°C.

Drugs for Neuropathic Pain / Anticonvulsants

N02BF02 - pregabalin ; Belongs to the class of gabapentinoids. Used to relieve pain and other conditions.

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