Methergine

Introduction 

• It is also known as Methylergonovine, Methylergobasin and D-lysergic acid 1-butanolamide.
• It is a synthetic drug from Ergot alkaloid.

Mechanism of Action

Methergine

• It is agonist action on 5HT,-receptor.
• Directly act on the smooth muscle of the uterus.
• Increase the tone, rate, and amplitude of rhythmic contraction.
• Thus it induced a rapid and sustained titanic stereogenic effect which shortens the 3 ^ prime stages of labor and reduces blood loss.

Classification

• "Therapeutic: Oxytocic
• Pharmacological: Ergotalkatoids
• Preganancy category: C

Indication

• PPH
• Refractory cluster headache (off-label)

Adr:

• Nausea
• Tinnitus
• "Vomiting
• Hypertension
• Transient chest pain
• Stomach Pain
• Diaphoresis
• Dyspnea
• Leg Cramps
• Foul taste
• Water intoxication
• Diarrhea
• Skin rashes
• Increased Sweating
• Hematuria.
• Headache
• Thrombophllbitis, Allergic reaction

Dosage form and Routes:

• Inj methergine 0.2 mgIN/IV in PRN; not to exceed 5 doses, Then 0.2-0.4 mg PO 96-98 hr PRN for 2-7 days.
• Administer IV only in Emergency because of the potential of HTN and CVA.
• Administer over 71 minutes and Monitor BP

Contraindication:

• Hypertension
• HSN
• Pregnancy
• Mitralvalve stenosis.
• "Toxemia
• Heart disease.
• Prolonged use. (may cause Cardiac retroperitoneal fibrosis)
• Cases of threatened spontaneous abortion.
• Breast feeding

Pharmacokinetics:

• Bioavailabity: 60% (Po), 78% (IM)
• Onset: 2-5 min after IM, immediately after IV
• Duration: 3 hr (PO), 3 hr (IM), 45 min/IV
• Metabolism: Liver
• Execration: Urine and feces
• Half-life: 1-5 min
• Distribution: Enter breast milk

Caution

• Second or third stage of labor prior to placenta delivery.
• Sepsis
• Hepatic impairment
• Renal impairment
• Peripheral vascular disease.
• Prolonged use may cause pleuropulmonary cardiac or retroperitoneal fibrosis.
• Pregnancy category: C

Nursing Consideration:

• Instruct patient to take medication as directed not to skip or double up on missed doses. If a dose is missed, omit it and return to the regular dose schedule.
• Advise patient that medication may cause menstrual-like cramps.
•  Caution patient to avoid smoking because nicotine constricts blood vessels.
• Instruct patient to notify Health Care Professional if an infection develops.
• Advice patient to notify health care professional of all Rx or OTC medication.