° Alcohol: ribose may increase the hypoglycemic effect of ethanol.120 ° Anti-diabetic drugs: ribose may increase the hypoglycemic effect of oral antihyper- glycemic agents.120
=> Salicylate drugs: ribose may enhance the hypoglycemic effect of salicylate drugs.120
• Cautions: insufficient reliable information available for use during pregnancy and lactation; avoid using.
=> Fibromyalgia: preliminary clinical research suggests that taking cholecalciferol reduces the pain that fibromyalgia patients experience.121 The greatest effects were in patients who also had low serum levels of vitamin D compared with that of placebo. Quality of life was not affected.121 The dose depended on the patient’s plasma vitamin D status, with patients taking 2400 IU daily if calcifediol levels were <60 nmol/L or 1200 IU daily if serum calcifediol were 60-80 nmol/L at baseline. Supplementation was conducted to achieve and maintain blood levels between 32 and 48 ng/mL for 20 weeks.121
° Aluminum: the protein that transports calcium across the intestinal wall can also bind and transport aluminum. This protein is stimulated by vitamin D, which may therefore increase aluminum absorption.122
° Atorvastatin/CYP 3A4 substrates: atorvastatin is metabolized in the gut by CYP 3A4 and vitamin D is thought to induce this enzyme, resulting in reduced bioavailability of atorvastatin and other CYP3A4 substrates.123
=> Calcipotriene: a vitamin D analog used topically for psoriasis that can be absorbed in sufficient amounts to cause systemic effects, including hypercalcemia. Tell patients not to take vitamin D supplements if they are taking calcipotriene.124
=> Cimetidine: inhibits an enzyme involved in the conversion of vitamin D to its active form in the liver. It does not affect the formation of active vitamin D metabolites in the kidneys.125
° Digoxin: high doses of vitamin D can cause hypercalcemia, and hypercalcemia increases the risk of fatal cardiac arrhythmias with digoxin. Avoid vitamin D above the tolerable upper intake level of 2000 units/day, and monitor serum calcium levels in people taking vitamin D and digoxin concurrently.124
° Non-dihydropyridine calcium channel blockers: high doses of vitamin D can cause hypercalcemia. Hypercalcemia can reduce the effectiveness of calcium channel blockers in atrial fibrillation.124
° Heparin and LMWH: unfractionated heparin is associated with reduced bone density and osteoporotic fractures, especially when doses of 15,000 units/day or more are used for 3 months or longer. Heparin can increase bone resorption and reduce bone formation.126
=> Thiazide diuretics: thiazide diuretics decrease urinary calcium excretion, which could lead to hypercalcemia if vitamin D supplements are taken concurrently.127
• Cautions: none known.
° Fibromyalgia: one clinical study suggests that taking acetyl L-carnitine 1000 mg per day orally plus acetyl-L-carnitine 500 mg/day IM for 2 weeks, followed by acetyl-L- carnitine 1500 mg/day orally for 8 weeks can reduce muscle pain and improve mood, general health, and quality of life compared to placebo in patients with fibromyalgia.'29 Another study showed that 1500 mg/day of acetyl-L-carnitine orally in three divided doses for 12 weeks improved depression symptoms, but not pain, quality of life, or anxiety, compared to baseline in patients with fibromyalgia.130
о Acenocoumarol: taking L-carnitine 1 gram/day seems to significantly increase the anticoagulant effect, similar to warfarin but shorter-acting. Use of acetyl-L-carnitine concurrently with warfarin can lead to increases in INR.131
° Warfarin: use cautiously with warfarin because acetyl L-carnitine can significantly increase the anticoagulant effect.130
• Cautions: insufficient reliable information available regarding use during pregnancy and lactation; avoid use.