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Biomedical subjects

C Farthing

Publications and source records attributed to C Farthing.

At least 19 recordsLinked to original sources
PubMed2005

Lowering the dose of hydroxyurea minimizes toxicity and maximizes anti-HIV potency.

The goal of this study was to optimize the hydroxyurea dosage in HIV-infected patients, and to minimize the toxicity and maximize the antiviral efficacy of the hydroxyurea-didanosine combination. In a randomized, open-label study (RIGHT 702, a multicenter trial performed in private and institutional practices), three daily doses (600 microg, 800-900 microg, and 1200 microg) of hydroxyurea were administered in combination with didanosine and stavudine to 115 chronically HIV-infected patients, one-third antiretroviral drug naive, with viremia between 5000 and 200,000 copies/ml regardless of CD4+ cell count. The primary efficacy end point was the proportion of patients with plasma HIV-1 RNA levels below 400 copies/ml after 24 weeks of therapy. In the RIGHT 702 intent-to-treat population the lowest (600 mg) dose of hydroxyurea was better tolerated, associated with fewer adverse events, and more potent by all efficacy parameters, including the primary end point (76 versus 60% patients with viremia<400 copies/ml at week 24 for the 600-mg and 800- to 900-mg dose groups, respectively; p=0.027), the mean area under the curve (60.3 versus 65.8; p=0.016), and the mean log10 decrease (-1.95 versus -0.77; p=0.001). Patients receiving 600 mg of hydroxyurea daily also had the highest CD4+ cell count, CD4+/CD8+ cell ratio, and lowest CD8+ cell count and percentage (p=0.035). The RIGHT 702 trial provides an explanation for the increased toxicity and decreased efficacy of hydroxyurea when it was used at high dosage (1200 mg daily). At the optimal dosage of 600 mg daily, hydroxyurea, in combination with didanosine, deserves reevaluation for the long-term management of HIV/AIDS worldwide, because of its excellent resistance profile, durability, and affordability.

Anti-HIV Agents↗
PubMed2001

Dose-escalation, phase I/II study of azithromycin and pyrimethamine for the treatment of toxoplasmic encephalitis in AIDS.

OBJECTIVE: To assess the safety, tolerance and activity of increasing doses of azithromycin in combination with pyrimethamine for the treatment of toxoplasmic encephalitis (TE) in patients with AIDS. DESIGN: A phase I/II dose-escalation study of oral azithromycin in combination with pyrimethamine. SETTING: Eight clinical sites in the United States. PATIENTS: Forty-two adult HIV-infected patients with confirmed or presumed acute TE. METHODS: Patients were enrolled into three successive cohorts receiving azithromycin 900, 1200 and 1500 mg a day with pyrimethamine as induction therapy. The induction period was 6 weeks followed by 24 weeks of maintenance therapy. MAIN OUTCOME MEASURES: Patient response was evaluated clinically and radiologically. RESULTS: Of the 30 evaluable patients, 20 (67%) responded to therapy during the induction period. Ten experienced disease progression. Of the 15 patients who received maintenance therapy, seven (47%) relapsed. Six patients discontinued treatment during the induction period as a result of reversible toxicities. Treatment-terminating adverse events occurred most frequently among the patients receiving the 1500 mg dose. CONCLUSION: The combination of azithromycin (900-1200 mg a day) and pyrimethamine may be useful as an alternative therapy for TE among patients intolerant of sulfonamides and clindamycin, but maintenance therapy with this combination was associated with a high relapse rate. The combination was safe, but low-grade adverse events were common.

AIDS-Related Opportunistic Infections↗
PubMed2001

Challenges of antiretroviral treatment in transient and drug-using populations: the SUN study.

This is an open-label, single-arm, phase 3b study (part of phase 3 development) to evaluate the efficacy and safety of Fortovase-soft gelatin formulation (saquinavir-SGC), combined with zidovudine (ZDV) and lamivudine (3TC), human immune deficiency virus type 1 in (HIV-1)-positive, antiretroviral-naive individuals. Forty-two HIV-1-positive adults with plasma HIV RNA >10,000 copies per milliliter (Roche Amplicor HIV Monitor assay) and CD4 cell count >100 cells/mm(3) were treated with SQV-SGC, 1200 mg three times per day; ZDV, 300 mg; and 3TC, 150 mg each twice per day for 48 weeks. High proportions were drug users (26%), demonstrated psychiatric disorders (alcohol abuse [14%]/depression [14%]), or were inadequately housed (5%). At 48 weeks, 50% of patients achieved viral suppression <400 copies per milliliter with 43% <20 copies per milliliter using an intent-to-treat analysis (missing values counted as virological failures). Corresponding proportions for patients remaining on therapy at 48 weeks were 91% <400 copies per milliliter and 78% <20 copies per milliliter. Most adverse events were mild. Saquinavir-SGC combined with ZDV and 3TC, achieved potent and durable HIV RNA suppression and was well tolerated over 48 weeks in an antiretroviral-naive population including high proportions of individuals considered difficult to treat, such as drug users, people with psychiatric problems and homeless individuals.

Adult↗
PubMed1999

Ritonavir and saquinavir combination therapy for the treatment of HIV infection.

OBJECTIVE: To evaluate the safety and antiretroviral activity of ritonavir (Norvir) and saquinavir (Invirase) combination therapy in patients with HIV infection. DESIGN: A multicenter, randomized, open-label clinical trial. SETTING: Seven HIV research units in the USA and Canada. PATIENTS: A group of 141 adults with HIV infection, CD4 T lymphocyte counts of 100-500 x 10(6) cells/l, whether treated previously or not with reverse transcriptase inhibitor therapy, but without previous HIV protease inhibitor drug therapy. INTERVENTIONS: After discontinuation of prior therapy for 2 weeks, group I patients were randomized to receive either combination (A) ritonavir 400 mg and saquinavir 400 mg twice daily or (B) ritonavir 600 mg and saquinavir 400 mg twice daily. After an initial safety assessment of group I patients, group II patients were randomized to receive either (C) ritonavir 400 mg and saquinavir 400 mg three times daily or (D) ritonavir 600 mg and saquinavir 600 mg twice daily. Investigators were allowed to add up to two reverse transcriptase inhibitors (including at least one with which the patient had not been previously treated) to a patient's regimen after week 12 for failure to achieve or maintain an HIV RNA level < or = 200 copies/ml documented on two consecutive occasions. MEASUREMENTS: Plasma HIV RNA levels and CD4+ T-lymphocyte counts were measured at baseline, every 2 weeks for 2 months, and monthly thereafter. Safety was assessed through the reporting of adverse events, physical examinations, and the monitoring of routine laboratory tests. RESULTS: The 48 weeks of study treatment was completed by 75% (106/141) of the patients. Over 80% of the patients on treatment at week 48 had an HIV RNA level < or = 200 copies/ml. In addition, intent-to-treat and on-treatment analyses revealed comparable results. Suppression of plasma HIV RNA levels was similar for all treatment arms (mean areas under the curve minus baseline through 48 weeks were-1.9, -2.0, -1.6, -1.8 log10 copies/ml in ritonavir-saquinavir 400-400 mg twice daily, 600-400 mg twice daily, 400-400 mg three times daily, and 600-600 mg twice daily, respectively). Median CD4 T-lymphocyte count rose by 128 x 10(6) cells/l from baseline, with an interquartile range (IQR) of 82-221 x 10(6) cells/l. The most common adverse events were diarrhea, circumoral paresthesia, asthenia, and nausea. Reversible elevation of serum transaminases (> 5 x upper limit of normal) occurred in 10% (14/141) of the patients enrolled in this study and was associated with baseline abnormalities in liver function tests, baseline hepatitis B surface antigen positivity, or hepatitis C antibody positivity (relative risk, 5.0; 95% confidence interval 1.5-16.9). Most moderate or severe elevations in liver function tests occurred in patients treated with ritonavir-saquinavir 600-600 mg twice daily. CONCLUSIONS: Ritonavir 400 mg combined with saquinavir 400 mg twice daily with the selective addition of reverse transcriptase inhibitors was the best-tolerated regimen of four dose-ranging regimens and was equally as active as the higher dose combinations in HIV-positive patients without previous protease inhibitor treatment.

Adult↗
PubMed1996

Pilot study of topical trifluridine for the treatment of acyclovir-resistant mucocutaneous herpes simplex disease in patients with AIDS (ACTG 172). AIDS Clinical Trials Group.

SUMMARY: Twenty-six AIDS patients were enrolled in an open label pilot study to evaluate the efficacy and toxicity of topical 1 percent ophthalmic trifluridine solution for the treatment of chronic mucocutaneous herpes simplex virus disease unresponsive to at least 10 days of acyclovir therapy. Susceptibility testing to acyclovir, trifluridine, and foscarnet was determined by plaque reduction assay. Twenty-four patients were evaluable for efficacy and 25 for toxicity analyses. Seven patients (29 percent) had complete healing of lesions. The overall estimated median time to complete healing was 7.1 weeks. An additional seven patients had > or = 50 percent reduction in lesion area. The overall estimated median time to 50 percent healing was 2.4 weeks. Ten (42 percent) patients discontinued treatment for reasons other than primary treatment failure and seven (29 percent) for failure to respond to therapy. Baseline patient characteristics associated with greater reduction in lesion area included higher Karnofsky score (p = 0.05), fewer lesions (p = 0.07), smaller lesion area (p = 0.11), and trifluridine susceptibility (p = 0.07). Eight (33 percent) patients developed new lesions outside of the treatment area while on study, reflecting the local nature of this therapy. No dose-limiting toxicity attributable to trifluridine was reported. Given the limited options for the treatment of acyclovir-resistant herpes simplex disease, topical trifluridine may be a useful alternative in selected patients.

AIDS-Related Opportunistic Infections↗
PubMed1994

Temporal association of cellular immune responses with the initial control of viremia in primary human immunodeficiency virus type 1 syndrome.

Virologic and immunologic studies were performed on five patients presenting with primary human immunodeficiency virus type 1 (HIV-1) infection. CD8+ cytotoxic T lymphocyte (CTL) precursors specific for cells expressing antigens of HIV-1 Gag, Pol, and Env were detected at or within 3 weeks of presentation in four of the five patients and were detected in all five patients by 3 to 6 months after presentation. The one patient with an absent initial CTL response had prolonged symptoms, persistent viremia, and low CD4+ T-cell count. Neutralizing antibody activity was absent at the time of presentation in all five patients. These findings suggest that cellular immunity is involved in the initial control of virus replication in primary HIV-1 infection and indicate a role for CTL in protective immunity to HIV-1 in vivo.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Idiopathic CD4+ T-lymphocytopenia--immunodeficiency without evidence of HIV infection.

BACKGROUND: The human immunodeficiency virus (HIV), the etiologic agent of the acquired immunodeficiency syndrome (AIDS), infects and depletes CD4+ T lymphocytes. Recently, patients have been described with profound CD4+ T-lymphocytopenia but without evident HIV infection, a condition now termed idiopathic CD4+ T-lymphocytopenia, and a national surveillance network has been set up to investigate such cases. METHODS: We studied 12 patients with CD4+ T-lymphocytopenia who were referred to us from three U.S. cities. Blood samples were tested for HIV with specific antibody assays, viral cultures, and polymerase-chain-reaction (PCR) techniques. RESULTS: The patients (10 men and 2 women) ranged in age from 30 to 69 years. Eight had risk factors for HIV infection. The clinical manifestations were heterogeneous: five patients had opportunistic infections, five had syndromes of unknown cause, and two had no symptoms. Two patients died from acute complications of their immunodeficiency. The patients' lowest CD4+ lymphocyte counts ranged from 3 to 308 per cubic millimeter (mean, 149). Three patients had complete or partial spontaneous reversal of the CD4+ T-lymphocytopenia. Concomitant CD8+ T-lymphocytopenia was noted in three patients, and abnormal immunoglobulin levels were found in five. Multiple virologic studies by serologic testing, culture, and PCR were completely negative for HIV in all patients. CONCLUSIONS: Our 12 patients with idiopathic CD4+ T-lymphocytopenia appear to be epidemiologically, clinically, and immunologically heterogeneous. It is unclear whether this syndrome is new, transmissible, or acquired. Many of the clinical and immunologic features are distinct from those found in AIDS, and our extensive virologic studies found no evidence of HIV infection. The cause of this condition remains unknown.

Adult↗
PubMed1991

The efficacy and safety of zidovudine with or without acyclovir in the treatment of patients with AIDS-related complex. The European-Australian Collaborative Group.

Our objective was to evaluate the efficacy and safety of zidovudine (250 mg every 6 h) alone or in combination with acyclovir (800 mg every 6 h) as treatment for AIDS-related complex (ARC). A double-blind, controlled clinical trial of 6 months therapy was conducted at teaching hospital ambulatory clinics in eight European countries and Australia; 199 patients were studied. Time to development of AIDS-defining opportunistic infections (OI) and AIDS-associated neoplasms, survival, performance status, body weight and CD4+ cell counts were measured. During the study six (9%) zidovudine recipients, five (7%) combination recipients and 12 (18%) placebo recipients developed AIDS-defining OI; the probability of developing an OI was 0.23, 0.09 and 0.08 for the placebo, zidovudine and combination recipients, respectively. Four patients in the placebo group, three in the zidovudine group and one in the combination group died during the study. Patients receiving zidovudine with or without acyclovir had moderate increases in CD4+ cell counts compared with placebo recipients and serum HIV p24 antigen level decreased significantly in all those receiving zidovudine. Fourteen (21%) patients in the zidovudine group and 16 (24%) in the combination group experienced bone-marrow suppression compared with three (5%) placebo recipients. Red-cell transfusions were administered to 6, 19 and 13% of placebo, zidovudine and combination recipients, respectively. These data confirm the efficacy of zidovudine therapy after 4 weeks' treatment in the reduction of development of OI in patients with ARC and support the use of a maintenance dose of 250 mg zidovudine 6-hourly. Given the increased development of OI in the treated groups compared with placebo during the first 4 weeks of therapy, we cannot exclude an initial adverse effect of zidovudine and recommend caution in the use of a loading dose of zidovudine. At 6 months there was no apparent difference in efficacy between the combination of zidovudine and acyclovir compared with zidovudine alone. Moreover, the addition of high-dose acyclovir resulted in a minimal increase in the risk of toxicity.

AIDS-Related Complex↗
PubMed1991

AIDS: a historical overview.

AIDS has been a recognized clinical entity now for just 10 years. In that time in the United States alone, it is estimated that 1 to 2 million people may be infected with HIV. Estimates of numbers infected worldwide are as high as 10 million. Over these 10 years, considerable progress has been made. The disease and all its protean manifestations have been accurately described. How HIV spreads and where it is spreading have been accurately recorded. The cause is known and well understood, with more detailed information available about HIV than about any other virus. Drugs that slow down the replication of HIV have been discovered and are in widespread use. A cure or vaccine, however, seems unlikely in the near future. The major hope for the present would appear to be continued education to prevent the spread of AIDS and better antiviral agents that will keep HIV suppressed and, ideally, soon allow infected individuals to lead a close-to-normal lifespan (if treatment is commenced at an early-enough stage in the course of the infection).

Acquired Immunodeficiency Syndrome↗
PubMed1990

Human immunodeficiency virus infection: a survey with special emphasis on mucocutaneous manifestations.

Since the first reports of acquired immunodeficiency syndrome (AIDS) in 1981, many dermatological conditions have been reported to occur more commonly in people infected with human immunodeficiency virus (HIV). Acute HIV infection may first present as a skin eruption; the onset of immunosuppression after years of infection with HIV may be heralded by the development of various viral, fungal, bacterial, papulosquamous, or neoplastic eruptions. HIV disease often presents first to dermatologists who must be aware of subtle presentations and the possibility of underlying HIV infection--as well as alert to danger signals that indicate the need for urgent treatment or referral.

Acute Disease↗
PubMed1989

The efficacy and toxicity of azidothymidine (AZT) in the treatment of patients with AIDS and AIDS-related complex (ARC): an open uncontrolled treatment study.

The efficacy and toxicity of oral azidothymidine has been studied in 145 patients with the acquired immunodeficiency syndrome (AIDS) or AIDS-related complex (ARC). The median survival time of AIDS patients on azidothymidine was 4.5 times higher when compared to a historical AIDS group who had not received the drug. This result must be interpreted with caution because of changes in treatment of HIV infection and growing awareness of AIDS which may have led to earlier diagnosis in the group treated with azidothymidine. The mortality was significantly higher in those patients who received transfusions and was particularly high in those who were transfused before azidothymidine. There was a significant difference in the occurrence of opportunistic infections in the patients who received transfusions compared with those who did not. AIDS patients treated immediately after an episode of Pneumocystis carinii pneumonia survived significantly longer than those in whom treatment was delayed for three months or more, and longer than those who were treated with azidothymidine because of another opportunistic infection or Kaposi's sarcoma. The T4 cell median counts increased in patients treated with azidothymidine reaching a peak at the end of the fourth month of treatment in the ARC group and at the end of the first month in the AIDS group with a subsequent fall in both groups. Sixty per cent of patients were p24 viral antigen positive at the start of treatment and 19 per cent of these patients had a fall of more than 50 per cent in antigen level while 32 per cent became antigen negative following treatment with azidothymidine. The mortality in the patients where the antigen disappeared or in whom there was a major fall of more than 50 per cent in antigen level was significantly less than in those where there was no change in antigen level. Twenty-nine patients were treated with azidothymidine because of skin Kaposi's sarcoma and in 17 tumour regressed or was stable. Thirty-two per cent of patients treated with azidothymidine became anaemic. Neutropenia occurred in 3 per cent of patients. Platelets increased initially after treatment but subsequently fell to thrombocytopenic levels in eight patients. Nine of 12 patients with thrombocytopenia before azidothymidine was commenced responded with an increased platelet count.

AIDS-Related Complex↗
PubMed1987

Treatment of cytomegalovirus pneumonitis with foscarnet (trisodium phosphonoformate) in patients with AIDS.

Foscarnet was administered to eight AIDS patients for suspected cytomegalovirus (CMV) pneumonitis as a continuous intravenous infusion for a minimum of 8 days. All the patients improved, three showing complete resolution of symptoms. Evidence of CMV infection from bronchoalveolar lavage samples was lacking in two patients. Adverse drug experiences consisted of thrombophlebitis, transient decreases in haemoglobin concentration, and reversible rises in serum creatinine levels.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Two regimens of sultamicillin in treating uncomplicated gonorrhoea.

Sultamicillin is a covalent union of ampicillin and the beta lactamase inhibitor, sulbactam (CP-45,899). Two studies were conducted to assess its efficacy in treating uncomplicated gonorrhoea. In the first study treatment comprised sultamicillin 1.5 g and probenecid 1 g; 124 (89.2%) of 139 patients responded including seven of 11 patients harbouring beta lactamase (penicillinase) producing strains of Neisseria gonorrhoeae (PPNG). In the second study sultamicillin 2.25 g and probenecid 1 g were given; 122 (93.8%) of 130 patients responded. Only two of seven pharyngeal infections resolved, and if pharyngeal infections are excluded the overall cure rate rose to 95.3%. Thirteen of 14 patients infected with PPNG strains were cured by the larger dose. Side effects were mild and transitory. It may be concluded that sultamicillin 2.25 g plus probenecid 1 g is an effective regimen to treat uncomplicated rectal and genital gonorrhoea and is useful for treating infections with PPNG strains. Most beta lactamase resistant antimicrobials must be given parenterally; sultamicillin is given by mouth.

Administration, Oral↗