Par Pharmaceutical begins shipment of generic Toprol-Xl

In November 2006, Par entered into a supply and distribution agreement with AstraZeneca in the US to distribute metoprolol succinate extended release tablets, as a substitute for Toprol-XL. Par began shipping 25mg tablets of generic Toprol-XL at that time.

Toprol-Xl is a beta-1-selective (cardioselective) adrenoceptor-blocking agent, for oral administration, available as extended release tablets. It has been formulated to provide a controlled and predictable release of metoprolol for once-daily administration.

Annual US sales of Toprol-Xl in the 50mg tablet are approximately $640 million, according to IMS Health.

Metoprolol succinate extended release is indicated for the treatment of hypertension, alone or in combination with other antihypertensives; the long-term treatment of angina pectoris; and the treatment of stable, symptomatic (NYHA class II or III) heart failure of ischemic, hypertensive, or cardiomyopathic origin. It was studied in patients already receiving ACE inhibitors, diuretics, and, in the majority of cases, digitalis.

In clinical trials of patients with hypertension and angina pectoris, the most common adverse events reported with immediate release metoprolol tartrate are tiredness (10%), dizziness (10%), depression (5%), diarrhea (5%), pruritus or rash (5%), shortness of breath (3%), and bradycardia (3%).