Antacids

• Antacid are alkaline compounds that neutralize stomach acid (localized to stomach)
• Antacids results

  • reduce pain associated with acid related disorders
  • do not coat ulcer to protect from gastric acid and pepsion
  • do not alter systemic pH due to poor absorption
  • does not prevent acid overproduction
• Antacids mechanism of action: react with gastric acid producing neutral salt which will decrease activity

  • decrease destruction of gut wall
  • reduce pepsin activity
  • increase mucosal protection by stimulating prostaglandin production
• OTC antacid meds

  • magnesium hydroxide milk of magnesia
  • calcium carbonate (tums)
  • aluminium hydroxide
  • calcium carbonate and magnesium hydroxide
  • magnesium and aluminium hydroxide (decreased diarrhea and constipation)
  • sodium bicarbonate (systemic effect)
• Antacid indication

  • peptic ulcer disease
  • GERD
  • prophylaxis against stress induced ulcer
• Antacids contraindications and precautions

  • pts with HTA or heart failure
  • avoid magnesium for pts with renal disease
  • administer 1h after administration of other drugs
  • effects last longer after a meal (30 min VS 3h)
• Drug interactions:

  • can influence dissolution and absorption of other drugs
  • increase or delay excretion of acidic drugs by alkalinizing urine
• Adverse effect

  • aluminium hydroxide: constipation
  • magnesium hydroxide: diarrhea
  • hypercalcemia
  • hypermagnesia