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氫氧化鎂

Magnesium Hydroxide

Magnesium hydroxide

抗酸劑 / 瀉藥PO狗貓馬牛羊山羊

別名: Milk of Magnesia · Magnalax · Carmilax · Polymag · Rumen Bolus · Instamag · Polyox · Laxade · Maalox · Phillips' Chewable · Magnesium/Aluminum Antacids

由 VetSheet 獸醫團隊審訂更新於 2026年4月5日本內容以實證獸醫文獻為本

5-15 mL/per dog per 24 hoursPO· q24h
5–15 ml — 每隻動物的固定劑量（不按體重換算）

劑量為持牌獸醫專業人員的臨床參考。請務必對照最新藥品說明書及個別病患確認。

各物種劑量

🌎 NA — North America🌍 EU — Europe

狗

適應症劑量途徑頻次療程地區
Adjunctive treatment of hypomagnesemia with GI disease and severe hypocalcemia5-15 mL/per dog per 24 hoursPOq24h—🌎 NA
Adjunctive therapy for gastric ulcers2-10 mL PO q2-4hPOq2-4h—🌎 NA
Antacid5-30 mL PO once to twice dailyPOq12-24h—🌎 NA
  • Adjunctive treatment of hypomagnesemia with GI disease and severe hypocalcemia: Using Milk of Magnesia
  • Adjunctive therapy for gastric ulcers: Using Aluminum hydroxide suspension or aluminum hydroxide/magnesium hydroxide suspension
  • Antacid: Using Milk of Magnesia

貓

適應症劑量途徑頻次療程地區
Antacid5-15 mL PO once to twice dailyPOq12-24h—🌎 NA
  • Antacid: Using Milk of Magnesia

馬

適應症劑量途徑頻次療程地區
Adjunctive gastroduodenal ulcer therapy in foals15 mL 4 times a dayPOq6h—🌎 NA
  • Adjunctive gastroduodenal ulcer therapy in foals: Using Aluminum/magnesium hydroxide suspension

牛

適應症劑量途徑頻次療程地區
Rumen overload syndrome (Adults)Up to 1 gram/kg (MgOH) mixed in 2-3 gallons of warm water and given PO per tube. May repeat (use smaller doses) at 612 hour intervals. If the rumen has been evacuated, do not exceed 225 grams initially.POq6-12h—🌎 NA
Rumen overload syndrome (Calves)As above but use ⅛th-¼th the amountPOq6-12h—🌎 NA
  • Rumen overload syndrome (Adults): Dehydration and systemic acidosis must be concomitantly corrected.

羊

適應症劑量途徑頻次療程地區
Rumen overload syndromeAs above for cattle, but use ⅛th-¼th the amountPOq6-12h—🌎 NA

山羊

適應症劑量途徑頻次療程地區
Rumen overload syndromeAs above for cattle, but use ⅛th-¼th the amountPOq6-12h—🌎 NA

劑量為持牌獸醫專業人員的臨床參考。請務必對照最新藥品說明書及個別病患確認。

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概覽

氫氧化鎂在獸醫學中用作口服抗酸劑和瀉藥。在小動物中，它曾被用於治療胃酸過多和潰瘍，但現在多被更有效的藥物取代；有時作為滲透性瀉藥使用。在反芻動物中，粉劑形式對於治療瘤胃過載症候群（瘤胃酸中毒）非常有效。

作用機制

Acts locally in the gastrointestinal tract:

  • Antacid: Neutralizes gastric hydrochloric acid (HCl) → raises gastric pH. Raising pH >4 minimizes pepsin proteolytic activity, reducing gastric mucosal damage.
  • Laxative: Poorly absorbed magnesium ions create an osmotic gradient → draws water into the intestinal lumen → distends the bowel → stimulates peristalsis.
  • Rumen Alkalinizer: Directly neutralizes excess lactic acid produced during grain overload → increases rumen pH and alters rumen microflora activity.

安全性與警告

禁忌症

  • Renal disease (due to risk of hypermagnesemia)
  • Gastric outlet obstruction (for aluminum-containing products)
  • Use cautiously in patients on sodium- or potassium-restricted diets (some products contain significant amounts)

不良反應

  • Diarrhea or frequent loose stools
  • Hypermagnesemia (especially in patients with severe renal insufficiency)
  • Constipation (if using combination products with aluminum)
  • Hypophosphatemia (with chronic use of aluminum-containing products)

注意事項

Magnesium-containing antacids are contraindicated in patients with renal disease. Oral magnesium hydroxide should only be used clinically in ruminants with documented rumen acidosis and should not be used for treatment of other suspected rumen disorders or hypomagnesemia. Chronic use may lead to electrolyte abnormalities.

藥物相互作用

Quinidine

Increased absorption or pharmacologic effect may occur

Sodium Polystyrene Sulfonate

May decrease the potassium-lowering effectiveness; may cause metabolic alkalosis in renal failure patients

Sustained-release medications

May alter absorption by changing GI transit times when used at laxative dosages

Sympathomimetic agents

Increased absorption or pharmacologic effect may occur

Fluoroquinolones

Decreased absorption (chelation); separate doses by at least 2 hours

Tetracyclines

Decreased absorption (chelation); separate doses by at least 2 hours

Azole Antifungals (Ketoconazole, Itraconazole)

Decreased absorption due to increased gastric pH; separate doses by at least 2 hours

Digoxin

Decreased absorption; separate doses by at least 2 hours

Iron Salts

Decreased absorption; separate doses by at least 2 hours

H-2 Antagonists

Decreased absorption; separate doses by at least 2 hours

Thyroid Hormones

Decreased absorption; separate doses by at least 2 hours

Corticosteroids

Decreased absorption; separate doses by at least 2 hours

Phenothiazines

Decreased absorption; separate doses by at least 2 hours

監測

  • Electrolyte imbalances (Magnesium, Phosphorus, Calcium) with chronic or high-dose therapy
  • Renal function
  • Fecal consistency

藥物動力學

吸收

Generally relatively non-absorbable, but up to 20% of an oral dose of magnesium can be absorbed.

排除

Absorbed magnesium is excreted by the kidneys.

過量

Chronic or acute overdose can lead to significant GI upset (severe diarrhea) and electrolyte imbalances (hypermagnesemia, especially in renal failure). Treat symptomatically with fluid therapy and correct electrolyte derangements.

可用產品

劑型

  • Oral Boluses
  • Oral Powder
  • Oral Liquid (Milk of Magnesia)
  • Chewable Tablets
  • Oral Suspension

獸醫用

  • Oral Boluses 17.9-27 grams (Magnalax, Carmilax, Polymag, Rumen Bolus, Instamag, Polyox II, Laxade)
  • Oral Powder 350-361 grams/lb (Carmilax Powder, Magnalax, Polyox, Laxade)
  • Milk of Magnesia 80 mg/mL in gallons

人用標示

  • Chewable Tablets: 311 mg & 400 mg (Phillips' Chewable, Pedia-Lax)
  • Oral Liquid (Milk of Magnesia): 400 mg/5 mL
  • Liquid concentrate: 800 mg/5 mL & 1,200 mg/5 mL
  • Aluminum Hydroxide and Magnesium Hydroxide Suspension (e.g., Maalox)

各地核准狀態

暫無法規資料: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU

儲存與穩定性

Store at room temperature in tight containers.

飼主須知

雖然這些產品可以在藥局直接購買，但未經獸醫指示，請勿定期給寵物服用。可能會引起腹瀉，請確保寵物有充足的飲水。為避免影響吸收，請與其他口服藥物間隔至少2小時服用。

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