Sodium bicarbonate drug interactions

Incompatibilities of metoclopramide depend on drug concentration, pH, and temperature. It is incompatible with cephalosporins, chloramphenicol, sodium bicarbonate, doxorubicin, cisplatin, and cyclophosphamide. Caution should be exercised with simultaneous administration of metoclopramide with lithium, sym-pathomimetics, antidepressants, bromocriptine, and carbamazepine. Omperazole interacts with tolbutamide, clarithromycin, and phenytoin. Coadministration of rantidine and cisapride increases the plasma concentration of rantidine. Abuse of senna laxative has been reported and may cause hepatitis.176-178... 

PROCAINE SOLUTIONS AMINOPHYLLINE, AMPHOTERICIN, BARBITURATES, MAGNESIUM SULPHATE, PHENYTOIN, SODIUM BICARBONATE Precipitation of drugs, which may not be immediately apparent A pharmaceutical interaction Do not mix in the same infusion or syringe... 

Antacids. See the relevant sections for the interactions of antacids. Antacids such as aluminium-, magnesium- and calcium-containing antacids and sodium bicarbonate reduce the absorption of iron and also of drugs that require an acidic pH in the stomach for their optimal uptake. 

Some others act extracellularly at non-ceUular constituents of the body without involving a drug-receptor interaction. The simplest example is that of the neutralization of gastric acid by antacid drugs. In this reaction the excess of gastric acid is neutralized by a base such as sodium bicarbonate. This reaction is not considered as a drug-receptor interaction, since no macro-molecular component is involved. Other types of extracellular mechanisms can be illustrated, for example, by the action of heparin which prevents blood coagulation. 

Information is very limited but it would appear that if rapid analgesia is needed with either mefenamic acid or tolfenamic acid, magnesium hydroxide can be given concurrently but aluminium hydroxide should be avoided. However, note that this applies to the fasted state, whereas NSAIDs are usually taken with or after food. Also note that magnesium hydroxide increased the endoscopically-detected gastric toxicity of ibuprofen in one study, see NSAIDs Ibuprofen and related drugs -i- Antacids , below. Aluminium hydroxide markedly reduces the speed of absorption. Sodium bicarbonate does not interact. Consider also NSAIDs Miscellaneous + Antacids , p.l42. 

Established interactions, but their clinical importance is still uncertain. The effects of these changes on the subsequent control of arrhythmias by fleeainide in patients seem not to have been studied, but the outcome should be well monitored if patients are given drugs that alter urinary pH to a significant extent (such as ammonium chloride, sodium bicarbonate). Large doses of some antacids may possibly do the same, but nobody seems to have studied this. 

Although changes in urinary pH can affect the amount of mexiletine lost in the urine, the effect of diet or the concurrent use of alkalinisers (sodium bicarbonate, acetazolamide) or acidifiers (ammonium chloride etc.) on the plasma concentrations of mexiletine does not appear to be predictable. There appear to be no reports of adverse interactions but concurrent use should be monitored. The UK manufacturer of mexiletine recommends that the concomitant use of drugs that markedly acidify or alkalinise the urine should be avoided. ... 

There appear to be no reports of adverse interactions between chlorpropamide and drugs that can alter urinary pH, but prescribers should be aware of the possibilities a reduced response if the pH is raised significantly and renal clearance predominates (e.g. with sodium bicarbonate, acetazolamide, some antacids) an increased response if the pH is made more acid than usual and metabolic clearance predominates (e.g. with ammonium chloride). Perhaps more importantly, the effects of drugs that alter the hepatic clearance of chlorpropamide are likely to be more significant when its renal clearance is low (i.e. when the urine is acid). ... 

Drugs that make the urine alkaline (e.g. sodium bicarbonate, carbonic anhydrase inhibitors) will reduce the elimination of memantine. Memantine should be used with caution with other NMDA antagonists, such as amantadine, ketamine and dextromethorphan, or concurrent use should be avoided, because of the theoretical increased risk of adverse effects. Memantine is predicted to interact with other drugs eliminated by the same renal secretion mechanism, but no important interaction was seen with glibenclamide, hydrochlorothiazide, metformin or triamterene. 

The interaction between ephedrine or pseudoephedrine and urinary alkalinisers are established but reports of adverse reactions in patients appear to be rare. Be aware that any increase in the adverse effects of these drugs (tremor, anxiety, insomnia, tachycardia, etc.) could be due to drug retention brought about by this interaction. Acetazolamide makes the urine alkaline and would be expected to interact with ephedrine and pseudoephedrine in the same way as sodium bicarbonate. 

---