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MANAGEMENT
OF OPPORTUNISTIC INFECTIONS
IN
HIV-POSITIV PATIENTS
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FACT
SHEETS
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Pneumocystis
carinii pneumonia (PUP)
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Initially
thought to be a protozoal infection. New data suggest
it is more closely related to fungi
Causative organism
Pneumocystis carinii
Symptoms of active infection
Fever, non-productive cough, shortness of breath, fatigue,
weight loss. Characteristic diffuse interstitial pulmonary
infiltrates on chest radiography. |
Diffuse small aciner shadows (arrows) with ground glass
appearance in both lower lobes suggestsPCP.
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Diagnostic procedures
Requires demonstration of organism in pulmonary secretions
or tissue. This is done by detecting organisms in bronchoalveolar
lavage or induced sputum.
Treatment
First choice is trimethoprim-sulfamethoxazole orally 2
DS tablets q 8 hours or trimethoprim i.v.
5 mg/kg plus sulfamethoxazole i.v. 25 mg/kg q 8 hours.
Alternatively, trimethoprim orally 320 mg q 8 hours plus
dapsone orally 100 mg o.d. Other alternative regimens
include atovaquone, clindamycin plus primaquine, and pentamidine.
Corticosteroids may be added to any of the above in moderate
to severe cases.
Prophylaxis
Secondary prophylaxis
Indicated in all cases after an initial episode of PCP,
and generally begins 2 weeks after short-term therapy
ends. The preferred regimen is trimethoprim-sulfamethoxazole
DS one tablet/day.
Primary prophylaxis
Indicated for a patient with absolute CD4 count <200
cells/ l or a CD4 percentage of less than 14%. The preferred
regimen is trimethoprim-sulfamethoxazole DS one tablet/day.
This is also effective prophylaxis against Toxoplasmosis.
Drug interactions
Trimethoprim-sulfamethoxazole
Trimethoprim-sulfamethoxazole interacts with warfarin,
sulfonylureas, methotrexate, phenytoin, thiazide diuretics
and cyclosporine.
Some physicians "desensitise" patients to trimethoprim-sulfamethoxazole
by starting with very low doses and gradually increasing.
Desensitization protocol for Trimethoprim (TMP)-sulfamethoxazole
(SMX)
Rapid desensitisation protocol: serial 10-fold dilutions
given over 4 hours |
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Time
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Dose (TMP/SMX)
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Dilution
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0
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0.004/0.02 mg
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1:10,000
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1
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0.04/0.2 mg
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1: 1,000
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2
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0.4/2.0 mg
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1: 100
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3
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4/20 mg
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1: 10
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4
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40/200 mg
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Tablet
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5
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160/800 mg
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Tablet
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Dapsone
Do not take within 2 hours of didanosine |
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