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- Pharmacology For Glyceryl Trinitrate
Glyceryl Trinitrate Pharmacology
Glyceryl TrinitrateAbout Glyceryl TrinitrateA vasodilator, Antianginal,in CHF.Mechanism of Action of Glyceryl TrinitrateIt is a direct smooth muscle relaxant, which have a prominent action vascular smooth muscles preferentially veins than arteries. It is enzymatically denitrated in the smooth muscle cells to release the reactive free radical nitric oxide which activates cytosolic guanylyl cyclase thus increases cyclic GMP levels which causes dephosphorylation of myosin light chain kinase(MLCK) through a cyclic GMP dependent protein kinase. Reduced availability of phosphorylated (active) MLCK interferes with activation of myosin and myosin fails to interact with actin to cause contraction and consequently relaxation occurs. Elevated levels of cyclic GMP also reduce calcium entry which also contributing to relaxation. It dilates veins more than arteries because veins have greater amount of enzyme that generate nitric oxide from nitrates. It also preferentially dilates epicardial arteries than autoregulatory arteries duo to differential distribution of nitrate metabolizing enzymes in these vessels.
It causes preload reduction, slight decrease in after load, and preferential relaxation of larger conducting coronary arteries and is used as an effective drug in the angina treatment.
Pharmacokinets of Glyceryl TrinitrateAbsorption: Well absorbed orally, But bioavailability is reduced due to first pass metabolism.
Distribution: Widely distributed in the body.
Metabolism: Metabolized in liver.
Excretion: Excreted mainly through urine as metabolites.
Onset of Action for Glyceryl TrinitrateSub lingual: 1 to 3 minutes
I.V.: 1 to 2 minutes
Topical: 30 to 60 minutes
Sustained release: 20 to 45 minutes
Duration of Action for Glyceryl TrinitrateSub lingual: 30 to 60 minutes
I.V.: 3 to 5 minutes
Topical: 2 to 12hours
Sustained release: 3to 8hours
Half Life of Glyceryl TrinitrateN/ASide Effects of Glyceryl Trinitrate1. Headache
7. Orthostatic hypotension
9. Sub lingual burning
Contra-indications of Glyceryl Trinitrate1. Hypersensitivity to nitrates
2. Severe hypotension
4. Hypertrophic cardiomyopathy
5. Cerebral haemorrhage
6. Early Myocardial infarction(sub lingual)
8. Along with phosphodiesterase inhibitors.
Special Precautions while taking Glyceryl Trinitrate1. Gradually withdraw the drug with caution, start therapy with lower doses
3. Blood volume depletion
4. Cardio vascular diseases
5. Pulmonary diseases
Pregnancy Related InformationUse with cautionOld Age Related InformationUse with cautionBreast Feeding Related InformationUse with cautionChildren Related InformationContraindicatedIndications for Glyceryl Trinitrate1. Angina pectoris
2. Unstable angina
3. Heart failure
4. Myocardial infarction
Interactions for Glyceryl TrinitrateAlcohol: Severe hypotension and cardiovascular collapse.
Aspirin: Increase serum concentrations of nitrates and their actions.
Antihypertensives, TCAs, Phenothiazine, Calcium channel blockers: Marked symptomatic orthostatic hypotension.
Sidenafil causes dangerous potentiation of hypotension, myocardial infarction and death
Lab Tests: May interfere with the Zlatkis-Zak colour reaction causing a false report of decreased serum cholesterol.Typical Dosage for Glyceryl TrinitrateTablets: 0.5mg at every 3 minutes until therapeutic effect is obtained.
I.V.: 5mcg/minute as infusion. Increase with increments of same dose
Sustained release Formulations: 2.5 to 6.5mg two to three times daily.
Topical: 1.5 to 3cm rubs on three times daily. Use more times if required.
Schedule of Glyceryl TrinitrateHStorage Requirements for Glyceryl TrinitrateStore in a well closed container at a temperature below 25 degree C. Protects from lightEffects of Missed Dosage of Glyceryl TrinitrateTake the missed dose as soon as noticed and if it is the time for next dose then skip the missed dose. Continue the regular schedule. Do not double the dose.Effects of Overdose of Glyceryl TrinitrateTreatment is supportive and symptomatic. Remove drug from the body by gastric lavage and administer activated charcoal to reduce absorption. Monitor blood gas measurements and methemoglobin levels. Supportive measures include respiratory support and oxygen administration. Recumbent positioning and passive movements of the extremities aid venous return. Maintain adequate body temperature and administer I.V. fluids. Administer adrenergic agonist like phenylephrine if required. For Methaemoglobinaemia; methylene blue may be given.
Home Delivery for Glyceryl Trinitrate in Your City
Medicine India is just a publishing medium for medicine related information and does not provide services or sales of medicines including glyceryl trinitrate.
However, we do publish a comprehensive directory of Pharmacies, Chemists and Druggists in cities all over India. You can use this directory to find the medicine stores in your city (or area) that provide home delivery services for glyceryl trinitrate and other medicines and health products. Home delivery services for glyceryl trinitrate may be free or they may cost you depending on the pharmacy and the minimum order requirements. It would be best to get this clarified while placing the order.
Please be aware that you should take glyceryl trinitrate only if a doctor has recommended or prescribed it. Some or all pharmacies who provide a home delivery service for medicines might insist on a prescription for glyceryl trinitrate before they complete the sale. You can get this information while placing the order for glyceryl trinitrate with the pharmacy.
Glyceryl Trinitrate is a generic medicine name and there are several brands available for it. Some of the brands for glyceryl trinitrate might be better known than glyceryl trinitrate itself. If the pharmacy that's willing to deliver medicines to your home doesn't have glyceryl trinitrate in stock, you can ask for one of the branded alternatives for glyceryl trinitrate.