cholecalciferol

Absorption: Unknown.

Distribution: Extensively protein bound.

Metabolism/Excretion: Undergoes activation in liver and kidneys to form calcitriol (active form of vitamin D₃).

Half-Life: 14 hr.

Time/Action Profile ⬆ ⬇

(effects on serum calcium)

ROUTE	ONSET	PEAK	DURATION
PO	unknown	unknown	unknown

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Hypercalcemia;
Vitamin D toxicity;
Concurrent use of magnesium-containing antacids or other vitamin D supplements;
Malabsorption problems.

Use Cautiously in:

OB: Safety not established.

Adv. Reactions/Side Effects ⬆ ⬇

Seen primarily as manifestations of toxicity (hypercalcemia)

CV: arrhythmias, hypertension

Derm: pruritus

EENT: conjunctivitis, photophobia

F and E: hypercalcemia

GI: ↑liver enzymes, anorexia, constipation, dry mouth, metallic taste, nausea, PANCREATITIS, polydipsia, vomiting, weight loss

GU: albuminuria, azotemia, polyuria

MS: bone pain, muscle pain

Neuro: headache, irritability, somnolence, weakness

Interactions ⬆ ⬇

Drug-drug:

Cholestyramine, colestipol, or mineral oil↓ absorption of vitamin D analogues.
Use with thiazide diuretics may result in hypercalcemia.
Corticosteroids↓ effectiveness of vitamin D analogues.
Concurrent use of magnesium-containing drugs may lead to hypermagnesemia.
Calcium-containing drugs may ↑ risk of hypercalcemia.
Concurrent use of other vitamin D supplements (↑ risk of hypercalcemia).

Drug-Food:

Ingestion of foods high in calcium content (see Food Sources for Specific Nutrients) may lead to hypercalcemia.

Route/Dosage ⬆ ⬇

PO (Adults ): 400–1000 IU daily.
PO (Infants ): Exclusively or partially-breastfed- 400 IU daily.

Availability ⬆ ⬇

(Generic available)

Tablets: 400 IU^OTC; 1000 IU^OTC
Oral solution: 400 IU/drop^OTC
In combination with: alendronate (Fosamax Plus D); See Appendix [not included in this PDA edition].

Assessment ⬆ ⬇

Assess for symptoms of vitamin deficiency prior to and periodically during therapy.
Assess patient for bone pain and weakness prior to and during therapy.
Observe patient carefully for evidence of hypocalcemia (paresthesia, muscle twitching, laryngospasm, colic, cardiac arrhythmias, and Chvostek’s or Trousseau’s sign). Protect symptomatic patient by raising and padding side rails; keep bed in low position.

Lab Test Considerations:

Monitor serum calcium, phosphorus, and alkaline phosphatase periodically.
- Serum calcium times phosphate product (Ca X P) should no exceed 70 mg²/dL² (patients may be at ↑ risk of calcification).

Toxicity and Overdose:

Toxicity is manifested as hypercalcemia, hypercalciuria, and hyperphosphatemia. Assess patient for appearance of nausea, vomiting, anorexia, weakness, constipation, headache, bone pain, and metallic taste. Later symptoms include polyuria, polydipsia, photophobia, rhinorrhea, pruritus, and cardiac arrhythmias. Notify health care professional immediately if these signs of hypervitaminosis D occur. Treatment usually consists of discontinuation of cholecalciferol, a low-calcium diet, or administration of a laxative. IV hydration and loop diuretics may be ordered to increase urinary excretion of calcium. Hemodialysis may also be used.

Implementation ⬆ ⬇

PO: May be administered without regard to meals.

Patient/Family Teaching ⬆ ⬇

Advise patient to take medication as directed. Take missed doses as soon as remembered that day, unless almost time for next dose; do not double up on doses. Advise parents to use calibrated measuring device or dropper with oral solution.
Review diet modifications with patient. See Food Sources for Specific Nutrients for foods high in calcium and vitamin D.
Encourage patient to comply with dietary recommendations of health care professional. Explain that the best source of vitamins is a well-balanced diet with foods from the 4 basic food groups and the importance of sunlight exposure.
Patients self-medicating with vitamin supplements should be cautioned not to exceed RDA. The effectiveness of megadoses for treatment of various medical conditions is unproved and may cause side effects.
Advise patient to avoid concurrent use of antacids containing magnesium.
Review symptoms of overdose and instruct patient to report these promptly to health care professional.
Emphasize the importance of follow-up exams to evaluate progress.

section name header

Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇