Vitamin drug-combination studies

Drug-combination studies In a randomised, double-blind, placebo-controlled study, the efficacy and safety of vitamins C and E supplementation in preventing post-operative atrial fibrillation was evaluated in 203 participants. No major adverse events occurred. The most frequently observed adverse events were dyspepsia and diarrhoea, and there were no significant differences in the frequency of adverse events between the vitamins supplemented and placebo groups [28 -]. 

Drug-combination studies No serious adverse events were observed in a 6-month trial of vitamin D and calcium supplementation in 159 healthy postmenopausal women [54 ]. A combination of calcitriol plus alendronate for supplementation of postmenopausal Korean women with early breast cancer and receiving aromatase inhibitor therapy was not associated with any serious adverse event [55 ]. The combination of vitamin D3 (1000 lU daily), calcium and omega-3 oils for treatment of osteopenia for 12 months was not associated with any adverse events... 

Drug-combination studies The effectiveness of Coenzyme QIO, vitamin E, selenium, and methionine in the treatment of chronic recurrent viral mucocutaneous infections in two clinical trials including a total of 157 patients [90=]. Significantly increased rates of healing and reduced incidents of relapse were observed in the intervention group compared with controls (p < 0.05). No adverse effects were reported. 

Gastrointestinal complaints (eg, nausea, diarrhea, vomiting, flatulence) are the most common adverse effects but rarely require discontinuation of therapy. Other potential adverse effects include headache and asthenia. Tenofbvir-associated proximal renal tubulopathy causes excessive renal phosphate and calcium losses and 1-hydroxylation defects of vitamin D, and preclinical studies in several animal species have demonstrated bone toxicity (eg, osteomalacia). Monitoring of bone mineral density should be considered with long-term use in those with risk factors for or with known osteoporosis, as well as in children. Reduction of renal function over time, as well as cases of acute renal failure and Fanconi s syndrome, have been reported in patients receiving tenofovir alone or in combination with emtricitabine. For this reason, tenofovir should be used with caution in patients at risk for renal dysfunction. Tenofovir may compete with other drugs that are actively secreted by the kidneys, such as cidofovir, acyclovir, and ganciclovir. 

There is now the acknowledgment that nutritional factors are indeed being studied for their role in combating mental problems. Thus, for example, a review article in the scientific literature by Kathleen M. Kantak titled Nutritional Aspects of Drug Action on Behavior, cited in the Bibliography, is representative. In this instance, the effects of (pure) tryptophan, magnesium/vitamin Bg, and vitamin C were examined, alone or in combination with drugs. There was an interaction even for such mental illnesses as schizophrenia, depression, autism, and hyperactivity. 

As AIDS research continued, the focus shifted to study of HIV protease. The crystallographic structure of HIV-1 was determined by Tom Blundell (1942- ) and coworkers at Birkbeck College in London in 1989. Blundell had studied under Dorothy Hodgkin, the Nobel laureate who solved the structures of penicillin, insulin, and vitamin B12. Study of the active site of HIV-1 protease combined with molecular modeling enabled the design of the family of protease inhibitors, the new anti-HIV drugs of the 1990s and beyond. 

Possibly, the elevated serum cobalamin in patients on VPA may be due to toxic effects on the liver. A higher level of circulating cobalamin does not necessarily indicate higher vitamin B stores in the liver. The reasons for B12 deficiency in patients on several AEDs may be due to the combined metabolic actions of drugs or an inadequate diet. In a study of 12 patients, PHT, PB and PRD had no effect on the absorption of vitamin B12 from the gut. 

---