quinine sulfate

quinine sulfate,

n brand names: Legatrin, M-Kya, Quinamm, Q-Vel;
drug class: antimalarial;
action: schizonticidal, but mechanism is unclear; increases refractory period in skeletal muscles;
uses: Plasmodium falciparum malaria, nocturnal leg cramps.

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quinine sulfate

Pharmacologic class: Cinchona alkaloid

Therapeutic class: Antimalarial

Pregnancy risk category X

Action

Unknown. Thought to interfere with DNA synthesis by increasing pH in intracellular organelles of susceptible parasites.

Availability

Capsules: 200 mg, 325 mg

Tablets: 260 mg

⊘Indications and dosages

➣ Chloroquine-resistant Plasmodium falciparum malaria

Adults: 650 mg P.O. q 8 hours for 3 to 7 days, given with another oral antimalarial

Children: 10 mg/kg P.O. q 8 hours for 7 days, given with another oral antimalarial

Off-label uses

• Nocturnal recumbency leg cramps

Contraindications

• Hypersensitivity to drug or other cinchona alkaloids
• G6PD deficiency
• Optic neuritis
• Tinnitus
• History of blackwater fever or thrombocytopenic purpura
• Pregnancy

Precautions

Use cautiously in:
• myasthenia gravis, recurrent or interrupted malaria therapy
• history of arrhythmias (especially prolonged QT interval), asthma, or heart disease
• breastfeeding patients.

Administration

• Give with or without food.

Route	Onset	Peak	Duration
P.O.	Unknown	1-3 hr	4-11 hr

Adverse reactions

CNS: headache, vertigo, syncope, apprehension, restlessness, excitement, confusion, delirium, dizziness, seizures

CV: angina, vasculitis

EENT: diplopia, amblyopia, blurred vision, scotoma, abnormal color perception, photophobia, night blindness, mydriasis, optic atrophy, hearing loss, tinnitus

GI: nausea, vomiting, diarrhea, abdominal cramps, epigastric pain, dysphagia

Hematologic: hemolytic anemia, hypoprothrombinemia, acute hemolysis, thrombocytopenic purpura, agranulocytosis

Hepatic: hepatotoxicity

Metabolic: hypothermia, hypoglycemia

Respiratory: asthma

Skin: rash, pruritus, photosensitivity, flushing, diaphoresis

Other: cinchonism, facial edema, hypersensitivity reactions including fever and hemolytic uremic syndrome

Interactions

Drug-drug. Aluminum-containing antacids: delayed or decreased quinine absorption

Cimetidine: decreased metabolism and increased effects of quinine

Digoxin: increased digoxin blood level

Mefloquine: increased risk of seizures, ECG abnormalities, and cardiac arrest

Neuromuscular blockers: increased effects of these drugs, leading to respiratory difficulty

Rifabutin, rifampin: increased metabolism and decreased effects of quinine

Succinylcholine: delayed succinylcholine metabolism

Urinary alkalizers (such as acetazolamide, sodium bicarbonate): increased quinine blood level and risk of toxicity

Warfarin: increased warfarin effects, increased risk of bleeding

Drug-diagnostic tests. Urinary 17-ketogenic steroids: elevated levels

Patient monitoring

☞ Monitor for signs and symptoms of hypersensitivity reaction, including fever and hemolytic uremic syndrome.
• Stay alert for signs and symptoms of cinchonism, including tinnitus, headache, nausea, and visual disturbances.
• Assess for bleeding tendency and hepatotoxicity.
• Monitor CBC, liver function tests, and quinine and glucose levels.
• Monitor patient for recumbency leg cramps. After several nights without such cramps, drug may be withdrawn.

Patient teaching

• Tell patient he may take with or without food.
☞ Teach patient to recognize and immediately report signs and symptoms of cinchonism and hepatotoxicity.
• Instruct patient to report unusual bleeding or bruising.
• Tell female patient to discuss pregnancy or breastfeeding with prescriber before taking drug.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.