Contraindications and Adverse Reactions
Endocrine System
Adverse Reactions to Drugs & Supplements
Summary
Most of the time, medicines make our lives better. They reduce aches and pains, fight infections, and control problems such as high blood pressure or diabetes. But medicines can also cause unwanted reactions.
One problem is interactions, which may occur between
- Two drugs, such as aspirin and blood thinners
- Drugs and food, such as statins and grapefruit
- Drugs and supplements, such as ginkgo and blood thinners
- Drugs and diseases, such as aspirin and peptic ulcers
Interactions can change the actions of one or both drugs. The drugs might not work, or you could get side effects.
Side effects are unwanted effects caused by the drugs. Most are mild, such as a stomach aches or drowsiness, and go away after you stop taking the drug. Others can be more serious.
Drug allergies are another type of reaction. They can be mild or life-threatening. Skin reactions, such as hives and rashes, are the most common type. Anaphylaxis, a serious allergic reaction, is more rare.
When you start a new prescription or over-the-counter medication, make sure you understand how to take it correctly. Know which other medications and foods you need to avoid. Ask your health care provider or pharmacist if you have questions.
Fruit Juices
MedlinePlus-Dietary Supplements
- Among all fruit juices, grape fruit juice (GFJ) possesses high interaction with almost all types of drugs. The juice modifies the body’s way of metabolizing the medication, affecting the liver’s ability to work the drug through a person’s system. Taniguchi in 2007 reported a case of purpura (blood spots, pooling of blood underneath the skin) associated with the ingestion of cilostazol, aspirin and grapefruit juice in 79 years old man. His purpura disappeared upon cessation of grapefruit juice, although his medication was not altered. The most probable cause of his purpura is an increase in the blood level of cilostazol because of the inhibition of cilostazol metabolism by components of grapefruit juice; Taniguch.
- Numerous reports have documented drug interactions with GFJ that occur via inhibition of CYP3A enzymes. Furanocoumarins present in GFJ inhibit the intestinal CYP 3A4 and have been shown to increase the oral bioavailability of medications that are CYP 3A4 substrates like Felodipine, midazolam, cyclosporine and raise their concentrations above toxic levels.
- GFJ is generally contraindicated to patients taking psychotropics and it is advised to inform patients about described interaction. The in vitro data suggest that compounds present in grapefruit juice are able to inhibit the P-gp activity modifying the disposition of drugs that are P-gp substrates such as talinolol. The overall exposure of some drugs can be increased by more than fivefold when taken with GFJ and increase the risk of adverse effects.
- With new anticonvulsants, serum iron and sodium need to be monitored. Additionally, users are advised to avoid drinking grape fruit juice within 1-2 hr(s) of taking these anticonvulsants. Furanocoumarines and active bioflavonoids present in GFJ are also inhibitors of OATP and when ingested concomitantly, can reduce the oral bioavailability of the OATP substrate, fexofenadine. Overall, a series of flavonoids present in GFJ are identified as esterase inhibitors, of which kaempferol and naringenin are shown to mediate pharmacokinetic drug interaction with most of the calcium channel antagonist and the statin groups of drugs such as enalapril and lovastatin due to their capability of esterase inhibition.
- Cholesterol-lowering agent lovastatin should be taken with food to enhance gastrointestinal absorption and bioavailability. The absorption of rosuvastatin, another anti-hyper lipidemic agent, was significantly decreased in the fed state compared with the fasting state, which suggests that rosuvastatin should be administered on an empty stomach.
- Simvastatin, Ezetimibe, pravastatin and fluvastatin may be taken without regards to food. However, high fiber diets may lower the efficacy of these drugs. Concomitant administration of statins with food may alter statin pharmacokinetics or pharmacodynamics, increasing the risk of adverse reactions such as myopathy or rhabdomyolysis or reducing their pharmacological action. Consumption of pectin or oat bran together with Lovastatin reduces absorption of the drug, while alcohol intake does not appear to affect the efficacy and safety of Fluvastatin treatment.
Antidiabetics
MedlinePlus-Diabetes Medicines
- Glimepiride is an antidiabetic and a new generation sulfonylurea derivative should be administered with breakfast or the first main meal of the day. It has absolute bioavailability and the absence of food interaction guarantee highly reproducible pharmacokinetics. Immediate release glipizide should be taken 30 minutes before meals. However, extended release tablets should be taken with breakfast. The maximum effectiveness of acarbose, an alpha-glucosidase inhibitor is attained when the drug is taken immediately at the start of each meal (not half an hour before or after), because it delays the carbohydrate absorption by inhibiting the enzyme alpha-glucosidase.
Analgesics and Antipyretics (Pain Reliever)
- Analgesics and antipyretics are used to treat mild to moderate pain and fever. For rapid relief, acetaminophen should be taken in an empty stomach because food may slow the body absorption of acetaminophen. Co-administration of acetaminophen with pectin delays its absorption and onset. NSAIDs like ibuprofen, naproxen, ketoprofen and others can cause stomach irritation and thus they should be taken with food or milk. Avoid or limit the use of alcohol because chronic alcohol use can increase the risk of liver damage or stomach bleeding. The absorption of ibuprofen and oxycodone when given in the combination tablet was affected by the concomitant ingestion of food.
- The Cmax and AUC0-alpha of ibuprofen were significantly increased after single and multiple doses of Coca-Cola, thereby indicating increased extent of absorption of ibuprofen. The daily dosage and frequency of ibuprofen must be reduced when administered with Coca-Cola. Food intake did not appear to affect the extent of absorption (ie, total exposure) of oral Diclofenac potassium soft gelatin capsule at doses.
Antitumor and Anticancer
MedlinePlus-Cancer Chemotherapy
- Mercaptopurine is a purine analog used for acute lymphoblastic leukemia and chronic myelogenous leukemias. Since it is inactivated by xanthine oxidase (XO), concurrent intake of substances containing XO may potentially reduce bioavailability of mercaptopurine. Cow’s milk is known to contain a high level of XO. This interaction may be clinically significant. Therefore most patients should try to separate the timing of taking mercaptopurine and drinking milk.
- Tamoxifen is a successful anti-tumor agent. If taken with sesame seeds, it negatively interferes with tamoxifen in inducing regression of established MCF-7 tumor size but beneficially interacts with tamoxifen on bone in ovariectomized athymic mice. Xue et al. had compared the influence of dietary elements on cancer progression, chemotherapy efficacy, and toxicity, particularly severe, late onset diarrhea related to irinotecan (CPT-11) treatment. They suggest that glutamine and n-3 fatty acids might be potentially useful adjuncts with CPT-11 treatment.
Cannabinoids
U.S. National Library of Medicine - PubMed Center
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Cannabinoid Related - FDA Recalls, Market Withdrawals and Safety Alerts
The list below provides information gathered from press releases and other public notices about certain recalls of FDA-regulated products. Not all recalls have press releases or are posted on this page. Certain product recalls sometimes merit expanded coverage due to the impact they have on public health. This section includes details of FDA's involvement in investigating recalls, a means to search recalled products, and information for consumers and industry representatives.
U.S. National Institutes of Health - MedlinePlus
MedlinePlus is a service of the National Library of Medicine (NLM), the world's largest medical library, which is part of the National Institutes of Health (NIH). Their mission is to present high-quality, relevant health and wellness information that is trusted, easy to understand, and free of advertising
National Center for Complementary and Integrative Health
The National Center for Complementary and Integrative Health (NCCIH) part of the National Institutes of Health, is the Federal Government’s lead agency for scientific research on the diverse medical and health care systems, practices, and products that are not generally considered part of conventional medicine. NCCIH was formerly known as the National Center for Complementary and Alternative Medicine.
Endocrine System
