Drug interactions between opioids and antiretroviral medications: interaction between methadone, LAAM, and nelfinavir

Understanding drug interactions between antiretrovirals and opiate therapies may decrease toxicities and enhance adherence, with improved HIV outcomes in injection drug users. We report results of a clinical pharmacology study designed to examine the interaction of the protease inhibitor, nelfinavir, with methadone and LAAM (N = 48). Nelfinavir decreased methadone exposure, but no withdrawal was observed over the five day study period. LAAM and dinorLAAM concentrations were decreased, while norLAAM concentrations were increased, with minimal overall change in LAAM/metabolite exposure. Methadone and LAAM did not affect nelfinavir concentrations, but methadone decreased M8 metabolite exposure. While no toxicities were observed, clinicians should be aware of the potential for drug interactions when patients require treatment with nelfinavir and these opiate medications.     

Interactions of oral antibiotics and common chronic medications

Geriatric patients often require precise dose titration of certain drugs for effective, non-toxic treatment of chronic disease. When short-term antibiotic therapy is required, an oral antibiotic that would minimally disrupt a finely-tuned chronic drug regimen would be most appropriate. Chronic medication-antibiotic interactions are potentially more common with the use of erythromycin, tetracyclines, and sulfonamides. Clinicians should use care, and monitor for drug interactions when these agents are combined with chronically used drugs such as theophylline, warfarin, or carbamazepine.     

Interactions between rhinitis and asthma.

Allergic rhinitis is present in up to 75% of patients with asthma, and in longitudinal follow-up, patients with allergic rhinitis are three times more likely to develop asthma as compared with subjects without allergic rhinitis. In experimental nasal challenges with allergen followed by nasal biopsies at 24 hours, there is positive staining for interleukin-5, eotaxin, intracellular adhesion molecule 1, vascular cell adhesion molecule 1, and E-selectin. Concurrently obtained bronchial biopsy specimens show eosinophils and intracellular adhesion molecule 1, vascular cell adhesion molecule 1, and E-selectin. There is increasing evidence for bone marrow stimulation by either seasonal or experimental allergen exposure resulting in an increase in bone marrow and peripheral blood progenitors for eosinophils/basophils. These cells then could populate the nose and lungs. From a therapeutic perspective, intranasal beclomethasone dipropionate and flunisolide have been reported to reduce the symptoms of asthma in patients with ragweed-induced allergic rhinitis. Conversely, high-dose orally inhaled budesonide has been shown to reduce some of the symptoms of allergic rhinitis. Finally, first reported in 1968 and then not until 1997, there is evidence that allergen vaccine immunotherapy, when administered to children with allergic rhinitis, may prevent the development of asthma or at least reduce its likelihood of occurring.     

Interactions between anticollagen antibodies and chondrocytes.

OBJECTIVE. To investigate the interactions between anticollagen antibodies and living chondrocytes. METHODS. Mouse monoclonal anti-type II collagen (anti-CII) antibodies, rabbit anti-human CII, and rat anti-CII, anti-CIV, anti-CV, anti-CVI, and anti-CIX were studied in vitro to determine their ability to bind to the plasma membrane of living bovine chondrocytes. RESULTS. Mouse monoclonal anti-CII, rabbit anti-CII, and rat anti-CII, anti-CV, and anti-CIX were shown to bind in vitro to the plasma membrane of bovine chondrocytes. Antibody binding was not observed with anti-CIV, or with chondrocytes previously incubated with bacterial collagenase. A significant increase in chondrocyte caseinase and collagenase secretion was observed following sequential incubation with the monoclonal antibodies and a source of activating cytokines. CONCLUSION. These results suggest that collagen autoantibodies may exert some of their pathogenic effects on cartilage through interactions with resident chondrocytes, leading to modulation of the rate of secretion of cartilage matrix-degrading enzymes.     

Microbial-gut interactions in health and disease. Interactions between dendritic cells and bacteria in the regulation of intestinal immunity

Dendritic cells (DCs) are immunoregulatory antigen-presenting cells. DCs can be potent activators of na?ve T cells and influence the generation and homing of effector lymphocytes; they can also induce regulatory mechanisms and maintain non-responsiveness. In part, these different outcomes are influenced by exposure of the DC to microbial products. The regulatory role of DCs is of particular importance at mucosal surfaces such as the intestine, where the immune system exists in intimate association with the external antigenic environment. Much of what we know about DCs has come from studies on the cells outside the gastrointestinal tract but information about gut DCs and their contribution to the specialized immune environment of the gut is now emerging. Here, we review current knowledge on gut DCs, suggest models for interactions between DCs and the commensal microflora in health and disease, and discuss gut DCs as targets for probiotic therapies.