HIV Myopathy

ChatGPT HIV myopathy is a muscle weakness condition in HIV-infected individuals, often caused by older HIV medications. Treatment typically starts with glucocorticoids like prednisolone or methylprednisolone, followed by a gradual tapering of the medication. Non-responders may try methotrexate or azathioprine. Monitoring for side effects is important. Physical and speech therapy, along with dietary precautions, can also help manage the condition.

Overview of HIV-Associated Myopathy

Human immunodeficiency virus (HIV) infection is associated with an inflammatory myopathy similar to polymyositis (PM). Patients usually experience progressive proximal muscle weakness involving the shoulder and hip girdles, nonspecific myalgia, and abnormal laboratory findings like elevated muscle enzymes (CK, aldolase, and aspartate transaminase), and abnormal electromyography. HIV myopathy generally has a better prognosis than idiopathic PM. Older-generation nucleoside reverse transcriptase inhibitors (zidovudine) have been linked to myopathy, which improves upon drug discontinuation. (1, 2, 3)

Initial Therapy for HIV-Associated Myopathy

Glucocorticoids are the cornerstone of initial therapy. They are typically initiated as either prednisolone (1 mg/kg per day for approximately 6 weeks) or for severely ill patients; methylprednisolone (1000 mg per day for three days) followed by tapering doses of prednisolone. Tapering is done over about 26 weeks, aiming to reach a daily dose of 5 mg, depending on clinical improvement. Most patients discontinue glucocorticoids at 9 to 12 months. Prophylaxis against osteoporosis and opportunistic infections with trimethoprim/sulfamethoxazole (TMP/SMZ) 160/800 mg is also necessary. (3, 4)

Options for Steroid Non-Responders

For patients who do not respond to steroids, therapeutic alternatives include methotrexate (starting at 15mg/week) or azathioprine (starting at 50 mg/day). (5)

Monitoring and Dose Adjustments for Methotrexate

Patients on methotrexate (MTX) should be regularly monitored for CBC, creatinine, and liver function tests. The MTX dose is adjusted based on creatinine clearance, and is generally avoided if creatinine clearance is below 30. Doses are delayed if neutrophils are below 1.0 or if platelets are below 100. Detailed dosing information can be found at the provided link. (6)

Non-Pharmacological Management

Physical therapy, including strength, isometric and resistive exercises, and speech therapy are vital non-pharmacological measures. They help prevent complications like aspiration in patients with esophageal dysfunction. Precautions may include elevation of the bed head, semi-thick diets, and the potential need for a nasopharyngeal or gastric feeding tube. (6)

References

1- Johnson RW, Williams FM, Kazi S, Dimachkie MM, Reveille JD. Human immunodeficiency virus-associated polymyositis: A longitudinal study of outcome. Arthritis Rheum. 2003;49(2):172–178.

2- Soriano V, Laguna F, Diaz F, et al. Pyomyositis in patients with HIV infection. AIDS. 1993;7(7) :1020–1021.

3- Sellier P, Monsuez JJ, Evans J, et al. Human immunodeficiency virus-associated polymyositis during immune restoration with combination antiretroviral therapy. Am J Med. 2000;109(6):510–512.

4- Johnson RW, Williams FM, Kazi S, Dimachkie MM, Reveille JD. Human immunodeficiency virus-associated polymyositis: A longitudinal study of outcome. Arthritis Rheum. 2003;49(2):172–178.

5-Authier FJ, Chariot P, Gherardi RK. Skeletal muscle involvement in human immunodeficiency virus (HIV)-infected patients in the era of highly active antiretroviral therapy (HAART). Muscle Nerve 2005; 32:247.

6-Bohan A, Peter JB. Polymyositis and dermatomyositis (first of two parts) N Engl J Med. 1975;292(7):344–347.