Parlodel (Bromocriptine Mesylate) - Drug Interactions, Contraindications, Overdosage, etc

DRUG INTERACTIONS

Drug Interactions

The risk of using Parlodel in combination with other drugs has not been systematically evaluated, but alcohol may potentiate the side effects of Parlodel. Parlodel may interact with dopamine antagonists, butyrophenones, and certain other agents. Compounds in these categories result in a decreased efficacy of Parlodel: phenothiazines, haloperidol, metoclopramide, pimozide. Bromocriptine is a substrate of CYP3A4. Caution should therefore be used when co-administering drugs which are strong inhibitors of this enzyme (such as azole antimycotics, HIV protease inhibitors). The concomitant use of macrolide antibiotics such as erythromycin was shown to increase the plasma levels of bromocriptine (mean AUC and Cmax values increased 3.7-fold and 4.6-fold, respectively).¹ The concomitant treatment of acromegalic patients with bromocriptine and octreotide led to increased plasma levels of bromocriptine (bromocriptine AUC increased about 38%).⁴ Concomitant use of Parlodel with other ergot alkaloids is not recommended. Dose adjustment may be necessary in those cases where high doses of bromocriptine are being used (such as Parkinson's disease indication).

OVERDOSAGE

The most commonly reported signs and symptoms associated with acute Parlodel^® (bromocriptine mesylate) overdose are: nausea, vomiting, constipation, diaphoresis, dizziness, pallor, severe hypotension, malaise, confusion, lethargy, drowsiness, delusions, hallucinations, and repetitive yawning. The lethal dose has not been established and the drug has a very wide margin of safety. However, one death occurred in a patient who committed suicide with an unknown quantity of Parlodel and chloroquine.

Treatment of overdose consists of removal of the drug by emesis (if conscious), gastric lavage, activated charcoal, or saline catharsis. Careful supervision and recording of fluid intake and output is essential. Hypotension should be treated by placing the patient in the Trendelenburg position and administering I.V. fluids. If satisfactory relief of hypotension cannot be achieved by using the above measures to their fullest extent, vasopressors should be considered.

There have been isolated reports of children who accidentally ingested Parlodel. Vomiting, somnolence and fever were reported as adverse events. Patients recovered either spontaneously within a few hours or after appropriate management.

CONTRAINDICATIONS

Hypersensitivity to bromocriptine or to any of the excipients of Parlodel^® (bromocriptine mesylate), uncontrolled hypertension and sensitivity to any ergot alkaloids. In patients being treated for hyperprolactinemia, Parlodel should be withdrawn when pregnancy is diagnosed (see PRECAUTIONS, Hyperprolactinemic States ). In the event that Parlodel is reinstituted to control a rapidly expanding macroadenoma (see PRECAUTIONS, Hyperprolactinemic States ) and a patient experiences a hypertensive disorder of pregnancy, the benefit of continuing Parlodel must be weighed against the possible risk of its use during a hypertensive disorder of pregnancy. When Parlodel is being used to treat acromegaly, prolactinoma, or Parkinson's disease in patients who subsequently become pregnant, a decision should be made as to whether the therapy continues to be medically necessary or can be withdrawn. If it is continued, the drug should be withdrawn in those who may experience hypertensive disorders of pregnancy (including eclampsia, preeclampsia, or pregnancy-induced hypertension) unless withdrawal of Parlodel is considered to be medically contraindicated.

The drug should not be used during the postpartum period in women with a history of coronary artery disease and other severe cardiovascular conditions unless withdrawal is considered medically contraindicated. If the drug is used in the postpartum period, the patient should be observed with caution.