Which drug inhibit the absorption of vitamin B12?
Which drug inhibit the absorption of vitamin B12?
Certain medications can decrease the absorption of vitamin B12, including: colchicine, metformin, extended-release potassium products, antibiotics (such as gentamicin, neomycin, tobramycin), anti-seizure medications (such as phenobarbital, phenytoin, primidone), medications to treat heartburn (such as H2 blockers …
What are strong inhibitors of CYP3A4?
Potent inhibitors of CYP3A4 include clarithromycin, erythromycin, diltiazem, itraconazole, ketoconazole, ritonavir, verapamil, goldenseal and grapefruit. Inducers of CYP3A4 include phenobarbital, phenytoin, rifampicin, St. John’s Wort and glucocorticoids.
What causes poor B12 absorption?
Your body also might not absorb enough vitamin B12 if: You have a disease that affects how nutrients are absorbed in your intestines, such as Crohn’s disease, HIV, or some infections. You have certain bad bacteria in your intestines. You take some medicines, such as antibiotics and anti-seizure drugs.
What are the contraindications of vitamin B12?
Who should not take VITAMIN B-12?
- low amount of potassium in the blood.
- Leber’s hereditary optic atrophy.
- inflammation of the stomach called atrophic gastritis.
- past history of complete removal of stomach.
Which form of B12 is therapeutic?
For maintenance therapy, 100-200 mcg once monthly is commonly used. Both cyanocobalamin and hydroxocobalamin forms are used.
Is grapefruit juice an inducer or inhibitor?
Grapefruit juice, a beverage consumed in large quantities by the general population, is an inhibitor of the intestinal cytochrome P-450 3A4 system, which is responsible for the first-pass metabolism of many medications.
What is the best form of vitamin B12?
Methylcobalamin (Methyl group + B12) the most active form of B12 seems to be better absorbed and retained in our tissues in higher amounts than the synthetic cyanocobalamin. Methylcobalamin is used much more efficiently by the liver, brain and nervous system.
Is there a drug interaction with CYP3A4?
This type of drug interaction is probably more frequent than commonly realized, since a reduced drug effect may be attributed sim- ply to lack of patient response. Many drugs that are CYP3A4 substrates, inhibitors, and inducers are also inhibitors or inducers of the ABC transport protein known as P-glycoprotein.
Which is an example of a CYP3A4 inhibitor?
A CYP3A inhibitor used to increase the systemic exposure of atazanavir or darunavir in combination with other antiretroviral agents in the treatment of HIV-1 infection. An anticonvulsant agent used with clobazam and valproate as an adjunct to treat refractory generalized tonic-clonic seizures in Dravet syndrome.
How are CYP3A4 and P-glycoprotein related?
Many drugs that are CYP3A4 substrates, inhibitors, and inducers are also inhibitors or inducers of the ABC transport protein known as P-glycoprotein. Many drug interactions, therefore, involve additive effects of both CYP3A4 and P-glycoprotein.
How is CYP3A4 sensitive to enzyme induction?
CYP3A4 is also sensitive to enzyme induction, and a number of drugs are known to be CYP3A4 inducers. CYP3A4 inducers tend to reduce plasma concen- trations of CYP3A4 substrates, resulting in reduced efficacy of the substrate.