Low-dose indinavir in combination with low-dose ritonavir: steady-state pharmacokinetics and long-term clinical outcome follow-up

OBJECTIVES

To evaluate the long-term efficacy and pharmacokinetics of indinavir (IDV)/ritonavir (RTV) 400/100 mg twice a day in combination with two nucleoside reverse transcriptase inhibitors.

METHODS

The study was retrospective with a prospective pharmacokinetic study at a single centre. All HIV-1-infected patients who started the regimen in the period from January 1999 to February 2001 were included in the study. Plasma HIV RNA and CD4 cell counts were recorded from baseline to week 120. Results were evaluated as intention-to-treat and on-treatment analyses with separate analyses for protease inhibitor naive and experienced patients. Patients who were still on the regimen by August 2001 were asked to participate in a pharmacokinetic evaluation.

RESULTS

Twenty-one patients started treatment with the regimen (median follow-up: 116 weeks). The percentage of patients with below 20 HIV-1 RNA copies/mL was 70.0% at week 120 and the median CD4 cell count increased from 320 to 607 cells/microL (P=0.062). The median IDV morning and evening Cmin were 434 ng/mL and 220 ng/mL, respectively.

CONCLUSIONS

Treatment with the IDV/RTV 400/100 mg regimen appears to be efficacious for up to 2 years. However, rather low IDV Cmin suggests that the regimen should be evaluated further before its widespread use and that the regimen probably should be guided by pharmacokinetic evaluation.

[Normocellular bacterial meningitis]

Bacterial meningitis is usually associated with pleocytosis of the cerebrospinal fluid due to the presence of polymorphonuclear leucocytes. However, 75 cases of bacterial meningitis without pleocytosis have been published. Normocellular bacterial meningitis accounts for 3.5% (1-42%) of all patients suffering from bacterial meningitis and is seen in all age groups: The finding can be explained by three different mechanisms including 1) lumbar puncture performed early in the course of meningitis, 2) immune deficiency, and 3) relative leucopenia due to severe sepsis. Normocellular bacterial meningitis is in general associated with a good prognosis except for cases with severe underlying diseases. A high concentration of bacteria in a normocellular cerebrospinal fluid might also indicate a poor prognosis.

[Endocarditis and normal cell meningitis caused by group B streptococci]

Bacterial meningitis usually presents with cerebrospinal pleocytosis with neutrophil predominance. Cases without pleocytosis are known from the literature. A case of group B streptococcal endocarditis with concomitant meningitis without cerebrospinal pleocytosis is described in a 40 year old woman. Finding the cerebrospinal fluid normocellular might mislead the physician and cause a delay in treatment.

[Pneumococcal endocarditis]

With the increasing frequency of pneumococcal bacteriaemia in Denmark during the last ten years, it is important to be aware of pneumococcal endocarditis. Two cases of pneumococcal endocarditis are described and an estimate is made of the incidence. The first case had endocarditis of the aortic valve with concomitant meningitis. Acute valve replacement was necessary and recovery was complete. The second case, which started with an embolic episode, also had endocarditis of the aortic valve. This patient recovered after treatment with antibiotics.

[Did pneumococcal endocarditis come back?]

Endocarditis caused by pneumococci represents 1-5% of all cases of endocarditis according to publications from different western countries. Necropsy studies show frequencies of up to 14% of all cases of endocarditis. It usually occurs as a complication to a pneumococcal pneumonia but other foci might be seen. Concomitant meningitis is seen in 20-85% of patients suffering from pneumococcal endocarditis. By knowing this disease entity there is a good possibility for treatment with antibiotics and valve replacement, but if overlooked the mortality is high. The frequency of pneumococcal endocarditis might be underestimated. Careful stethoscopic examination for heart murmurs should be a part of the clinical examination in case of invasive pneumococcal disease, especially with concomitant meningitis. Since bacteriaemia due to pneumococci is diagnosed with increasing frequency in many Northern European countries, special attention should be paid to pneumococcal endocarditis. The literature is reviewed with reference to pathology, pathogenesis, frequency, clinical presentation, diagnosis, treatment and prognosis.

[Gluteal hematoma infected with multiresistant Salmonella typhi]

Salmonella infections usually presents with diarrhea and fever. Localized salmonella infection with abscess formation is an uncommon but significant manifestation of salmonellosis. An infected gluteal haematoma caused by multi resistant Salmonella typhi is described. Etiologic diagnosis, appropriate chemotherapy, surgical intervention and isolation is important. There was no nosocomial infections related to this case and treatment was effective. It is important to be aware of unusual manifestations of salmonella infections, which may occur without any previous history of exposure.

[Bone marrow disease revealed by leukocyte scintigraphy in a patient with relapsing fever of unknown origin]

A patient with relapsing fever of unknown origin and initially normal findings on bone-marrow biopsy was further investigated by leucocyte scintigraphy, which showed lack of uptake in the bone-marrow. Repeated bone-marrow biopsy and histological examination of a peripheral lymph node established the diagnosis of Hodgkin's disease.