Nucleoside reverse transcriptase inhibitor (NRTI) drugs are medications that interfere with the function of the enzyme reverse transcriptase, making it impossible for retroviruses like HIV to replicate. Some of the earliest HIV/AIDS drugs developed and approved for use, like AZT, are examples of NRTI drugs. People most typically take the medication as part of combination therapy with other medication, and it may be necessary to adjust the treatment regimen for the patient to receive the best benefit.
Also known as nucleoside analogs or nukes, short for “nucleoside,” these drugs work by binding to reverse transcriptase. When viruses attempt to use this enzyme to turn single strands of RNA into DNA as part of their lifecyle, the NRTI drugs insert false genetic code, preventing successful replication and stopping the viral life cycle. HIV can become resistant to NRTI drugs, along with other medications, and this is one reason patients may need to adjust their drug regimens over time.
Some examples of drugs in this family include tenofovir, abacavir, and stavudine. Patients may be able to purchase medications packaged on their own, or as part of a combination with another compound. Combination medications can make multiple drug regimens easier by providing patients with doses of two or medications at once. This reduces the number of pills people need to take.
Antiretroviral drugs like NRTI drugs can work in a number of ways. In combination therapy, they attack a virus from multiple angles. If the virus does not respond well to one drug or starts to develop resistance, another drug can slip past its defenses. The medications have to be taken on a consistent schedule to work effectively and patients need regular follow-up visits to check on viral loads and see if their immune systems are responding.
Like other medications, there can be contraindications for NRTIs. Some medications do not work well with these drugs, and patients in therapy for multiple chronic illnesses may need to carefully balance their medications to achieve the best treatment outcomes. Patients can also develop allergies and other adverse reactions and commonly experience side effects like weight loss, nausea, and diarrhea. Patients should keep track of their side effects and consult a doctor if they experience severe illness or start to develop problems like difficulty breathing. A doctor can try adjusting dosages or changing medications to see if these measures will resolve the problem and make the patient feel more comfortable.