Myoprost

Carboprost tromethamine.

Each mL contains Carboprost (as tromethamine) USP 250 mcg, benzyl alcohol 9.450 mg.
A clear, colorless solution, free from visible particles.

Pharmacotherapeutic group: Prostaglandins. ATC code: G02AD04.
Pharmacology: Pharmacodynamics: Carboprost is a synthetic 15-methyl analogue of dinoprost (prostaglandin F2 alpha). It is a uterine stimulant with a more prolonged action than dinoprost and when used in post-partum haemorrhage, it stimulates the uterus to contract in a manner similar to that normally observed in the uterus following delivery. The resulting myometrial contractions provide haemostasis at the site of placentation and hence prevent further blood loss. Whether or not this action results from a direct effect on the myometrium has not been determined with certainty at this time. The fundamental actions of the prostaglandins include inhibition or stimulation of smooth muscle contraction and inhibition of the release of noradrenaline or modulation of its effects at neuro effector sites. They affect the uterus, the cardiovascular system, the gastro-intestinal system, the nervous system, the urinary system and metabolic processes.
Pharmacokinetics: The presence of the methyl group delays inactivation by enzymic dehydrogenation.
Peak plasma levels vary depending on the route of administration. In the Rhesus monkey after a single I.M. injection of 20-30 micrograms of 15-methyl PGF2 alpha peak levels of 0.4-5 nanograms/ml resulted at 30-60 minutes, declining to baseline levels 6-8 hours after injection. In pregnant women, an I.M. injection of 100-400 micrograms resulted in peak plasma levels of 1-1.6 nanograms/ml 20-30 minutes after injection. Levels declined to 0.2-0.4 nanograms/ml after 3 hours. When I.M. doses of 250 micrograms were given every two hours, pre-injection plasma levels stabilized after four injections at 1.2 nanograms/ml.

Uterotonic (prostaglandin).

Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration whenever solution and container permit. An initial dose of 250 micrograms (1.0 ml) should be administered as a deep intramuscular injection. If necessary, further doses of 250 micrograms may be administered at intervals of approximately 1.5 hours. In severe cases the interval between doses may be reduced at the discretion of the attending physician, but it should not be less than 15 minutes. The total dose should not exceed 2 mg (8 doses).

Treatment of overdosage must be symptomatic at this time, as clinical studies with prostaglandin antagonists have not progressed to the point where recommendations may be made. If evidence of excessive side-effects appears, the frequency of administration should be decreased or administration discontinued.

It should not be used where the patient is sensitive to Carboprost Tromethamine or any of the excipients. Acute pelvic inflammatory disease. Patients with known active cardiac, pulmonary, renal, or hepatic disease. It is contraindicated in pregnancy.

Carboprost Tromethamine should be used by medically trained personnel and is available only to hospitals and clinics with specialised obstetric units where 24 hour resident medical cover is provided. It should be used only with strict adherence to recommended dosages.
This preparation should not be used for induction of labour.
It must not be given intravenously.
Special caution is necessary in patients with history of asthma, hypo- or hypertension, cardiovascular, renal, or hepatic disease, glaucoma or raised intra-ocular pressure, anaemia, jaundice, diabetes, or epilepsy.

Fertility: There are no clinical data on the effects of Carboprost Tromethamine on fertility.
Pregnancy: Studies in animals have shown reproductive toxicity and any dose which produces increased uterine tone could put the embryo or fetus at risk.
Lactation: There are no data on the excretion into breast milk for Carboprost Tromethamine

Carboprost Tromethamine can cause serious breathing difficulties as well as asthma and wheezing. Less frequent, but potentially more serious, adverse effects are elevated blood pressure, dyspnoea and pulmonary oedema. Other less serious adverse effects noted include chills, headache, diaphoresis, dizziness and injection site erythema and pain.

As it can potentiate the effect of other oxytocics, concomitant use is not recommended.

Store in a refrigerator at 2° to 8°C. Do not freeze.

Drugs Acting on the Uterus

G02AD04 - carboprost ; Belongs to the class of prostaglandins. Used to induce abortion or augment labour and to minimize blood loss from the placental site.

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