The Medicines and Healthcare products Regulatory Agency has for the first time approved generic versions of a class of medicines that are used to treat adult and paediatric patients who have been infected by HIV and weigh at least 40kg.

The medicines, called raltegravir, reduce the amount of HIV in a patient’s blood when used with other medicines by preventing an enzyme known as HIV integrase, which allows the virus to multiply in cells in the body, from working. Raltegravir also increases a patient’s CD4-cell count, a type of white blood cell that helps maintain a healthy immune system.

“The active ingredient raltegravir is an antiviral medicine prescribed as a 600mg film‑coated tablet,” the MHRA said, insisting Raltegravir must be used in combination with other HIV medicines. Its recommended dosage is 1,200mg as two 600mg tablets taken orally once a day.

The MHRA said its approval of the medicine was “supported by evidence from studies in healthy volunteers” but insisted it would “keep the safety and effectiveness of raltegravir under close review.”

Its deputy director of innovative medicines Shirley Hopper said: “Ensuring timely access to generic medicines is a key priority for us. Appropriate data have been provided to assure us that these medicines are the same as, and considered interchangeable with an already licensed reference medicine, called Isentress."

The MHRA added: “Studies have been limited to tests to determine that it is bioequivalent to the reference medicine. Two medicines are bioequivalent when they produce the same levels of the active substance in the body. As raltegravir generics have been shown to be bioequivalent to the reference medicine, their benefits and possible side-effects are considered to be the same as the reference medicine.”

The MHRA said patients who experience any side-effects, as listed on its website, should talk to their doctor, pharmacist or nurse.