A CASE REPORT: DRUG INTERACTION BETWEEN LINEZOLID AND DOPAMINE
Linezolid is a weak, non-selective inhibitor of monoamine oxidase (MAO). It can inhibit the breakdown of the tyramine by MAO in the gut and can also potentiate the effect of tyramine at nerve endings, thereby causing an increase in blood pressure. We encountered a neonate who developed acute hypertensive episode after simultaneous administration of dopamine and linezolid. A 25 w preterm neonate was admitted in NICU (Neonatal Intensive Care Unit) with complaints of Patent Ductus Arteriosus and respiratory infection. Linezolid infusion 6.5 mg every 8 h over 30 min (7 am, 3pm, 11 pm) was added after confirmation of gram-positive cocci (Staphylococcus epidermis) growth. Inj. Dopamine 20 mcg/kg/min was started for derangement in blood pressure 52/28 mm Hg (Mean blood pressure 43) at 5 pm. The baby developed acute hypertensive episode at 5.30 pm for which dopamine was withdrawn immediately. The half-life of Linezolid is 5.6 h in preterm baby, and that of Dopamine is 2 min. Since the probability of peak concentration for both the administered drugs was around the same time period, the baby developed acute hypertensive episode. So the combination of Linezolid with Dopamine should be avoided if possible or the dosage interval has to be extended to minimize the adverse reaction.
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