nisha
Forum Guru
Topics: 146
Posts: 919
|
A 37-year-old, HIV-positive man comes for evaluation of generalized weakness, diffuse muscle pain, and frequent headaches that began eight weeks after the start of new HIV medications. He has never had any symptoms from his HIV infection, and he has a CD4 of 255/ƒÊL and an HIV RNA viral load of 25,000 (by PCR). He was recently started on zidovudine, lamivudine, and ritonavir/lopinavir. His past medical history is significant for hypertension and hypercholesterolemia. His medications include simvastatin and metoprolol. His physical examination is significant for diffuse muscle tenderness of the extremities. The range of motion is decreased because of pain with movement. His potassium level is 5.4 mEq/L, serum bicarbonate is 16 mEq/L, BUN is 35 mg/dL, creatinine is 1.6 mg/dL, and his viral load is RNA 40,000. The genotyping test result is pending. What will you do while waiting for this result?
(A) Switch zidovudine and lamivudine to didanosine and stavudine, and continue ritonavir
(B) Switch zidovudine, lamivudine, and ritonavir/lopinavir to didanosine, stavudine, and indinavir, and stop simvastatin
(C) Continue all medications but stop simvastatin
(D) Continue zidovudine and lamivudine, and switch ritonavir/lopinavir to efavirenz
(E) Switch to didanosine, stavudine, and efavirenz, and stop simvastatin
___________________
IM resident
|
| phuluong2k
Forum Fanatic
Topics: 714
Posts: 2,008
|
My turn to guess
C
|
| catmd
Forum Senior
Topics: 7
Posts: 129
|
C.
|
| mani
Forum Guru
Topics: 104
Posts: 1,403
|
i will choose E. Options are tricky. With C, i m worried about deslipidemia caused by ritonavir, pt is already high risk for cardiovascular disease (history of HTN and hyperlidemia) D can be ok but pt is having statin induced myositis. But we need to do something for his hyperlidemia if we r removing statin
Edited by mani on 11/02/05 - 05:32 PM
___________________
Sincerity and hard work are the keys to success!
|
| muhaammad azeem1
Forum Newbie
Topics: 0
Posts: 31
|
i think mani has a reson
|
| muhaammad azeem1
Forum Newbie
Topics: 0
Posts: 31
|
i think mani has a reson E
|
| nisha
Forum Guru
Topics: 146
Posts: 919
|
Answer: (E) Switch to didanosine, stavudine, and efavirenz, and stop simvastatin Explanation: This patient presents with a drug interaction between the protease inhibitors and the HMG-CoA reductase inhibitor. In this case, it is with ritonavir and simvastatin. This can produce significant toxicity from the statin. Ritonavir can increase the serum concentration of simvastatin, causing severe myalgias, rhabdomyolysis, and potential renal insufficiency. The next necessary step is to stop simvastatin or change the protease inhibitor to a non-nucleoside reverse-transcriptase inhibitor, such as efavirenz. However, in this case, the patient also presents with failure to achieve a reduction in HIV viral load of 1 log after eight weeks of therapy. In the event of inadequate treatment of HIV infection, the best choice would be to start two new nucleoside reverse-transcriptase inhibitors (NRTIs) and use efavirenz instead of ritonavir, in addition to discontinuing the simvastatin. It is not enough to change ritonavir to indinavir because high-level cross-resistance is very likely. Genotyping guides the therapeutic choice of all treatment failures. The best thing to do when treatment is insufficient is to use as least two, and preferably three, new drugs.
___________________
IM resident
|
| nisha
Forum Guru
Topics: 146
Posts: 919
|
Yes Mani...good reasoning!
___________________
IM resident
|
| lucky
Forum Guru
Topics: 23
Posts: 505
|
mani , i salute u!!!
|
|
| |
| | | | | | | | | |
