The cost of drugs prescribed under the NHS has risen from £4.9bn in the financial year 1999-2000, to £7.13bn in the year ended in April, a 50% rise.

The annual number of prescriptions over the same period rose from 541m to 632m, a 17% rise.

The figures were released yesterday in the annual report of the NHS chief executive, Sir Nigel Crisp. Asked if the NHS was getting good value for the £7.13bn, Sir Nigel said: "That is a good question. We are in negotiation with the drug industry over where we are going with the pharmaceutical price regulation scheme."

The scheme controls the price of drugs to the NHS, and is next due to be renegotiated in September 2004.

The Serious Fraud Office is investigating one case of alleged price-fixing by a manufacturers' cartel.

Prescriptions for the family of drugs known as statins, which reduce cholesterol in the bloodstream, rose from 8.1m in 2000 to 19m this year.

The number of patients treated by the NHS continues to rise, according to the report. Hospital admissions for non-urgent treatment rose 9% in the past three years, to 5.32m. Numbers treated in outpatient clinics and by GPs have also risen, the report claims, although no figures are available for 1999-2000 for comparison.

Waiting times have fallen, with the number waiting longer than a year down from 16,689 in September 2002 to 114 this September.