LACTOLOGY FOUNDATION

Magaldrate (ATC A02AD02) is a complex aluminium–magnesium antacid used for symptomatic treatment of acid‑related disorders and, based on current evidence, can be considered compatible with breastfeeding when used in usual doses for short periods, but is unsuitable for chronic or high‑dose use, especially in women or infants with renal impairment. In a lactological framework, it reasonably falls into an intermediate risk category: not an absolute contraindication during lactation, yet relatively unfavourable compared with better‑studied acid‑suppressive alternatives, so restriction of dose and duration and preference for other drugs in long‑term therapy are advisable.

Drug identity and pharmacology

Magaldrate is a complex salt described as hydrated aluminium–magnesium sulphate hydroxide; structurally it is a penta‑aluminium deca‑magnesium hydroxide/sulphate complex with a high molecular weight, formulated to act as a non‑systemic antacid. It belongs to ATC group A02AD (combinations and complexes of aluminium, calcium and magnesium compounds) and specifically to A02AD02, magaldrate.

Pharmacologically, magaldrate neutralises gastric hydrochloric acid and increases intragastric pH; in contact with acid, it is converted to aluminium hydroxide and magnesium hydroxide, which exert local antacid and adsorbent effects on gastric mucosa. Standard indications include symptomatic treatment of gastro‑oesophageal reflux, esophagitis, acute and chronic gastritis, gastric and duodenal ulcer disease, and other conditions associated with episodic hyperacidity.

Toxicological profile in adults

In adults with normal renal function, magaldrate is generally well tolerated when used short‑term at recommended doses, but its aluminium and magnesium content underlies several toxicological concerns. Gastrointestinal adverse effects are common and dose‑dependent: magnesium components may cause diarrhea, while aluminium components may cause constipation, chalky taste and, rarely, intestinal discomfort or black stools; severe GI symptoms warrant discontinuation and evaluation.

Systemically, aluminium and magnesium absorption from magaldrate after postprandial administration appears very low; a recent human study showed no measurable aluminium absorption and magnesium absorption within normal ranges after oral dosing. Nevertheless, aluminium may accumulate during prolonged high‑dose therapy, particularly in patients with chronic kidney disease, increasing risks of osteomalacia, microcytic anemia and encephalopathy, while magnesium accumulation can lead to hypermagnesaemia with neuromuscular and cardiac toxicity in renal failure. Therefore, magaldrate is contraindicated or should be avoided in significant renal impairment, in patients on magnesium‑restricted diets, and in those concurrently receiving other aluminium‑containing drugs or citrate salts that enhance aluminium absorption.

Regarding pregnancy, reference sources classify magaldrate as pregnancy risk category C, reflecting limited controlled human data and cautious use only when potential benefit justifies potential fetal risk. Toxicologically, prolonged or excessive use in pregnancy is discouraged, and safer alternatives (for example, selected H2‑blockers or proton‑pump inhibitors with better pregnancy data) may be preferred for chronic therapy.

Lactation risk and lactological assessment

From a lactation toxicology perspective, the key determinants are poor oral bioavailability and minimal passage into breast milk of aluminium and magnesium from magaldrate. An expert lactation database describes magaldrate as compatible with breastfeeding, stating that aluminium and magnesium concentrations in milk do not increase significantly, that any aluminium transferred appears in trace amounts, and that adverse effects have not been reported in breastfed infants. The same source nonetheless advises avoiding chronic or excessive use and recommends follow‑up of the infant when the mother is treated.

General breastfeeding guidance from major organisations emphasises that most medicines taken by the mother reach breast milk only in tiny amounts and are usually safe, but particular caution is warranted in premature infants, newborns and babies with renal or other serious health problems. In line with this, magaldrate should be avoided or used only exceptionally in mothers of very preterm or renally impaired infants, where even small aluminium or magnesium loads could theoretically be more problematic. For healthy term infants, short‑term maternal use at standard doses is unlikely to pose a clinically relevant risk, especially when dosing occurs after breastfeeding and total daily exposure is limited.

Your current Bulgarian‑language page correctly highlights the high aluminium and magnesium content of magaldrate, lists a paediatric contraindication below 12 years in some product information, and consequently adopts a conservative lactological position, categorising magaldrate as toxicological lactation category III and recommending temporary cessation of breastfeeding until full maternal elimination of the drug before resuming lactation. This stance is more restrictive than that of some international lactation references, which consider magaldrate compatible or moderately safe; however, it is consistent with a precautionary toxicological philosophy aiming to minimise infant exposure to aluminium, especially given the paucity of robust long‑term data.

In a summarised lactological assessment, magaldrate (A02AD02) can be characterised as:

• Suitable for short‑term use in breastfeeding mothers of healthy term infants when clearly indicated, at the lowest effective dose and for the shortest duration.
• Relatively unfavourable for prolonged or high‑dose therapy during lactation, especially in the presence of maternal renal impairment or vulnerable infants; for such cases, alternative acid‑suppressive regimens with better‑documented breastfeeding safety (for example famotidine, omeprazole) are preferable.
• In line with a strict toxicological framework such as yours, appropriately placed in an intermediate or “use with caution / consider alternatives” lactation category (analogous to category III), with consideration of temporary breastfeeding interruption only when high doses, long durations or infant risk factors make theoretical toxicity more concerning.