Drotaverine hydrochloride (2% solution for injections in vials)
Solutio Drotaverini hydrochloride 2% pro injectionibus
International not patented name
Drotaverine
Pharmacotherapeutic group
Vasodilatators. Myotropic spasmolytics.
Composition
1 ml of the solution for injections contains 20 mg of drotaverine hydrochloride.
Pharmacologic action
Pharmacodynamics
Myotropic spasmolytic. The chemic structure and pharmacologic characteristics are close to those of papaverine but drotaverine possesses a stronger and more prolonged effect. It reduces the ionized calcium entering non-striated muscles cells because of inhibiting phosphodiesterase and cAMP intracellular accumulation.
It exerts a pronounced and long time action on the non-striated muscles of the internal organs and vessels. It dilates the blood vessels, causes a moderate decrease of arterial pressure, increases the minute volume of the heart, has a certain anti-arrhythmic effect. It reduces the cerebral vessels tonus and increases their blood filling. It practically does not effect on the vegetative nervous system and does not penetrate into the central nervous system. Drotaverine does not have anti-cholinergic effect that is why unlike chinolytic spasmolytics it may be applied for managing glaucoma.
Pharmacokinetics
95 – 98% of it fixes with plasma proteins. It is distributed evenly in tissues, penetrates into non-striated muscles cells. It does not pass through the HEB. The preparation is excreted mostly by the kidneys, in a smaller volume with the bile. The period of the preparation half elimination when injected intravenous is 2.4 hours.
Indications
Spasm of the internal organs non-striated muscles (cardio- and pylorospasm), chronic gastroduodenitis, gastric and duodenal ulcers, cholelithiasis (hepatic colic), chronic cholecystitis, postcholecystectomic syndrome, hypermotor dyskinesia of bile ducts, spastic dyskinesia of intestine, intestinal colic caused by the gases retention after operations, colitis, proctitis, tenesmus, meteorism, urolithiasis (renal colic), pyelitis, spasm of cerebral vessels, of coronary and peripheral arteries, need for the uterine contractions weakening and for removing the neck of the uterine spasm in labor, spasm of non-striated muscles during instrumental interferences, dysmenorrheal, strong labor pains.
Drotaverine hydrochloride may be applied as an additional drug for hypertonic crises as well.
Mode of application and dosing regime
The preparation is indicated for intramuscular, subcutaneous, intravenous injections.
The average 24 hour dose is 40 – 240 mg divided into 1 – 3 intramuscular or subcutaneous injections 2 – 4 ml of 2% solution each for adults and children older 12.
In case of acute hepatic and/or renal colic the preparation in injected intravenous slowly the dose being 40 – 80 mg (2 – 4 ml of 2% solution).
When the peripheral blood circulation is changed (obliterating endarteritis, Raynaud’s disease) intra-arterial injections (slow) are possible.
For shortening the phase of the neck of the uterine opening during the physiologic labor at the beginning of the extension drotaverine hydrochloride is injected intramuscular as a single dose of 40 mg, when the effect is not satisfactory it is reinjected once within 2 hours.
Special warnings
Intravenous and intra-arterial injections are made only under the specialist’s supervision, willingly in hospital. When the preparation is injected intravenous the patient should lie for a danger of collapse exists.
After the parentherental and especially after the intravenous injection the patient should neither drive a car nor work using complicated machines during one hour.
The preparation appliance is limited for patients with adenoma of prostate (because of the urinary bladder detrusor weakening urination difficulty may occur); it should be applied with care in case of a pronounced atherosclerosis of coronary arteries, of close angle glaucoma.
The preparation is allowed to be prescribed to pregnant women only after thorough considering the ratio of the real benefit for the mother and of the potential risk for the fetus. As soon as the necessary clinical data are absent appliance of the preparation during the lactation period is not recommended. In case a necessity arises the breast feeding should be stopped for the period of the preparation receiving.
Side effects
After the parentheral injection (mostly after the intra venous one) appearance of feeling of heat, dizziness, headache (rarely), insomnia are possible; arrhythmia (rarely), hypotension, tachycardia, sweating, nausea, constipation may be observed. In some patients, especially in persons being hypersensitive to bisulphites allergic reactions – allergic dermatitis as a rule – are possible; extremely rarely in asthmatic patients or in those having had allergic reactions in the anamnesis anaphylactic reactions, bronchospasm are possible.
Contraindications
Hypersensitivity to the active component (drotaverine hydrochloride) or to an excipient; severe hepatic or renal failure, severe heart failure (syndrome of low heart discard), AV blockade II and III grades, cardiogenic shock, arterial hypotension, childish age younger 12.
Interaction with other medicines
It enhances other spasmolytics effect (including M-cholinblockers), hypotension caused by three-cyclic anti-depressants, quinidine, procainamide. It reduces the morphine spasmogenic activity, anti-parkinsonic properties of levodopa (tremor and rigidity increase are observed).
Phenobarbital improves the spasm removal reliability.
Overdosing
Symptoms: collapse, atrioventricular blockade, cardiac arrest, respiratory center paralysis.
Treatment: symptomatic therapy (specific antidote does not exist).
Dosage form
Solution for injections 2% in 2 ml vials (1 vial contains 40 mg of drotaverine hydrochloride). Five vials in a pack or in a contour cellular pack.
