LABETALOL injectable

Therapeutic action

• Non cardioselective beta-blocker

Indications

• Hypertension in pregnancy, in case of severe symptoms or when oral treatment is not possible

Forms and strengths, route of administration

• 100 mg ampoule (5 mg/ml, 20 ml) for IV injection

Dosage

Dosage should be adjusted according to blood pressure (BP). The goal is to reduce the blood pressure to 140/90 mmHg. Diastolic BP must not fall below 90 mmHg.

• One dose of 20 mg (4 ml) over at least one minute. If hypertension remains uncontrolled 5 and 10 minutes after injection, administer another dose of 20 mg (4 ml). Administer additional doses of 40 mg (8 ml) then 80 mg (16 ml) at 10 minute intervals as long as hypertension is not controlled (max. 300 mg total dose).

Duration

• According to clinical response.

Change to oral treatment as soon as possible.

Contra-indications, adverse effects, precautions

• Do not administer to patients with asthma, chronic obstructive bronchopneumonia, heart failure, severe hypotension, bradycardia < 50/minute, atrio-ventricular heart blocks, Raynaud's syndrome, hepatic impairment.
• May cause:
  • bradycardia, orthostatic hypotension, heart failure, bronchospasm, hypoglycaemia, gastrointestinal disturbances, dizziness, headache, weakness, urinary retention;
  • abrupt fall in maternal blood pressure with placental hypoperfusion and foetal death when administered too rapidly by IV injection or in case of overdose.
• Administer with caution to patients with diabetes (risk of hypoglycaemia).
• Reduce dosage in patients with renal impairment.
• Do not exceed recommended dosage and administration rate. During administration, monitor maternal BP and heart rate, as well as foetal heart rate.
• In the event of anaphylactic shock, risk of resistance to epinephrine.
• Avoid or monitor combination with: mefloquine, digoxin, amiodarone, diltiazem, verapamil (risk of bradycardia); tricyclic antidepressants, neuroleptics, other anti- hypertensive drugs (risk of hypotension).
• Monitor the newborn: risk of hypoglycaemia, bradycardia, respiratory distress occurring most often during the first 24 hours and until 72 hours after the birth.
• In the event of hypotension, administer Ringer lactate to maintain diastolic BP ≥ 90 mmHg.
• Breast-feeding: no contra-indication

Remarks

• Labetalol IV is also used in the treatment of hypertensive crises with serious end-organ damage.

Storage