Therapeutic action: The combination of metamizole with the vitamins of B group in that preparation is used for influence either on the pain and the inflammation or on numerous important processes and functions of nervous system. Metamizole besides its strong analgesic and antipyretic activity possesses also some anti-inflammatory activity and antispasmodic effect on the smooth muscles. Neuralgin is tolerated well regarding its ulcerogenous effects, which differs it from many other preparations of hat group. It provokes analgesic effect mainly of peripheral type but influences also the excitement threshold in thalamus and the conduction of extero- and interoreceptive pain impulses in CNS. Vitamin B1 lacks pharmacodynamic activity in therapeutic doses but it possesses various physiologic functions.
Vitamin B1 after absorption is transformed in the organism to thiamine pyrophosphate that is a coenzyme of enzymes which take part in the decarboxylation of pyruvic and a-ketoglutaric acid. Its lack leads to accumulation of lactic and pyruvic acid flint could provoke polyneuritis, beri-beri in case of avitaminosis and severe hypovitaminosis, Wernicke encephalopathy and Korsakoff syndrome, alcoholic polyneuropathy and disturbances of the heart function. Its daily absorption is limited from 8 to 15 mg. Toxic effect is seen after prolonged peception only. There are rarely cases of hypersensitivity.
Vitamin B6 has also a slight pharmacodynamic activity. The physiologic functions of Vitamin B6 and of its metabolite pyridoxaiphosphate as a coenzyme, include the integration in several metabolite transformations of the amino acids. It takes part in the transformation of 5-hydroxytryptamine, of methionine into cysteine. Deficiency of Vitamin B6 could develop in insufficient nutritional supply, disturbed intestinal absorption reception of drugs which are its antagonists, radiotherapy. The symptoms of deficiency are manifested with seborrhea like lesions around eyes, nose, glossitis, stomatitis; peripheral neuritis, seizures, anemia.
Vitamin B12 does not exert pharmacodynamic activity. The psychological significance of the active coenzymes methylobalamin and 5-deoxyadenosincobalamin is essential for the cellular growth and replication. It participates in the processes of transmethylation and transportation of hydrogen cations in the synthesis of choline, methionine, creatinine and nucleic acids. It takes an important part in the processes of hemopoesis. It exerts favourable activity on the function of liver and nervous system. The Vitamin B12 lack is manifested with symphoms of the side hemopoietic and nervous system.
What is it used for? : Severe and difficult for relieving pains of different origin; headache, tooth-ache, pains in the joints, muscles, following traumas and operations, gall and kidney colics, neuritis, neuralgias, traumatic cerebrasthenia; inflammation of upper respiratory ways of microbial or virus origin, chorea; febrile states.
Contraindications and Cautions: Allergy to some of the vitamins and analgin or to preparations of the same group; agranulocytosis anemia, acute thromboembolism, erthytrosis and erhythemia, hepatic porphyria, bronchial asthma. It should be carefully administered in patients with hypotension and angina pectoris; children under 14, glucose-6-phosphate deficiency.
Side effects: The adverse reactions are provoked mainly by metamizole. It is observed: loss of appetite, vomiting, allergic skin reactions, anathylactic reactions, epileptic-like seizures (in very large doses only). Sometimes in case of reception of a single dose over than 1 g it is possible to observe hypotension The risk for provocation of agranulocytosis is proven to be minimal one but its importance necessitates serious attention. There are reports for separate cases of acute kidney failure and interstitial nephropathy in metamnizole usage. Neurotoxicity with slight signs of dependence could develop in prolonged reception of 200 mg of Vitamin B6
Interactions: Vitamin B6 the antiparkinsonic effect of L-dopa because of stimulation of dopadecarboxylase. The metabolism of Vitamin B6 is disturbed in simultaneous reception of oral contraceptives. Antagonists of Vitamin B6 are: isoniazid, penicillamine, cycloserine, thiosomicarbazones (the effects are reduced).
When metamizole is administered as a single dose it inhibits the drug metabolism and in prolonged treatment it could induce some drug metabolising enzymes. The risk for allergies is higher in concomitant reception with other antipyretics, analgesic and anti-inflammatory agents. There is a risk for damaging of the white blood cells in reception of suppressing the bone marrow function golden preparations, anticancer agents, etc.
The neuroleptic and tranquillising drugs enhance the analgesics activity of neuralgin. Some antidepressants, the oral contraceptives and allopurinol inhibit the metabolism of the preparation and can augment its toxicity. It can provoke extreme cooling when is taken together with chlorpromazine. It decreases the blood level of cyclesporine A and can disturb its action.