One-alpha

alfacalcidol

Brand(s):

• Alfacal

Manufacturer:

• Macleods

Disease(s):

• Osteoporosis / Hypocalcemia / Hypophosphatemia / Osteodystrophy / Rickets / Prophylaxis / Secondary Hyperparathyroidism / Tetany / Vitamin D Deficiency /

One-Alpha Capsules: A Comprehensive Guide

What is One-Alpha?

One-Alpha capsules contain alfacalcidol, an active form of vitamin D. Unlike regular vitamin D (cholecalciferol), alfacalcidol doesn't require further activation by the kidneys. This makes it a more direct and efficient way to boost vitamin D levels, especially crucial for those with impaired kidney function. Alfacalcidol plays a vital role in calcium regulation and bone metabolism, impacting various systems including the gut, bones, parathyroid glands, muscles, and even the brain. Its broad effects are why it's often preferred over plain vitamin D in specific situations.

Indications for One-Alpha

One-Alpha is prescribed for conditions where calcium metabolism is disrupted due to poor 1-α hydroxylation, often linked to reduced kidney function. Key uses include:

• a) Renal osteodystrophy: Bone disease associated with kidney failure.
• b) Hyperparathyroidism (with bone disease): Overactive parathyroid glands causing bone problems.
• c) Hypoparathyroidism: Underactive parathyroid glands leading to low calcium levels.
• d) Neonatal hypocalcaemia: Low calcium in newborns.
• e) Nutritional and malabsorptive rickets and osteomalacia: Bone disorders due to vitamin D deficiency or poor absorption.
• f) Pseudo-deficiency (D-dependent) rickets and osteomalacia: Bone disorders where the body can't properly use vitamin D.
• g) Hypophosphataemic vitamin D resistant rickets and osteomalacia: Rare bone disorders resistant to vitamin D treatment.

Dosage and Administration

Always follow your doctor's instructions precisely. One-Alpha is administered orally as a capsule, ideally taken with food.

Adult Oral (PO): The usual starting dose is 1 mcg/day. Maintenance doses typically range from 0.25 mcg to 1 mcg/day.

Adult Intravenous (IV): The recommended initial dose is 1 mcg per dialysis session, administered two to three times a week. IV administration is usually reserved for specific clinical scenarios.

Contraindications

One-Alpha should not be used if you have: hypersensitivity to alfacalcidol or any capsule components; hypercalcemia (high blood calcium); or metastatic calcification (calcium deposits in tissues).

Important Considerations Before Use

Regular monitoring of serum calcium and phosphate levels is essential, particularly in children, individuals with kidney problems, and those taking high doses. Other blood tests such as PTH (parathyroid hormone), alkaline phosphatase, and calcium phosphate levels may also be necessary based on the patient’s condition.

Hypercalcemia (high calcium levels) is a potential side effect. Patients should be aware of symptoms like muscle and bone pain, weakness, confusion, dehydration, nausea, vomiting, constipation, increased urination, and headache. If hypercalcemia develops, treatment should be stopped until calcium levels normalize. Once levels return to normal (usually within a week), One-Alpha may be restarted at a reduced dose.

Prolonged hypercalcemia can worsen conditions like arteriosclerosis, cardiac valve problems, or kidney stones. Therefore, close monitoring is crucial in patients with these conditions. Kidney function may temporarily or persistently decline. Caution is advised in patients with lung calcification (potential for cardiac complications) and granulomatous diseases (like sarcoidosis) due to increased sensitivity to vitamin D.

Concurrent use with digitalis glycosides (heart medications) may increase the risk of cardiac arrhythmias if hypercalcemia occurs.

One-Alpha capsules contain sesame oil, which can rarely cause severe allergic reactions.

Pregnancy

Limited data exists on alfacalcidol use during pregnancy. Animal studies have shown reproductive toxicity at high doses. Therefore, One-Alpha is not recommended during pregnancy or for women of childbearing age who aren't using contraception.

Breastfeeding

While not definitively proven, increased levels of 1,25-dihydroxyvitamin D are likely to be present in breast milk of mothers using One-Alpha. This could affect the infant's calcium metabolism. Breastfed infants of mothers taking alfacalcidol should be carefully monitored for hypercalcemia.

Fertility

There are no clinical trials on One-Alpha's impact on fertility. Preclinical studies in rats did not indicate fertility issues.

Possible Side Effects

Hypercalcemia: Early symptoms may include nausea, vomiting, weakness, headache, drowsiness, dry mouth, constipation, and muscle/bone pain. Severe hypercalcemia can manifest as increased urination, thirst, loss of appetite, weight loss, eye irritation, pancreatitis, skin issues, and potentially, more serious cardiovascular and kidney problems.

• Gastrointestinal: Loss of appetite, nausea, vomiting, diarrhea, increased thirst.
• Central Nervous System: Headache, dizziness, fatigue.
• Skin: Increased sweating, itching, rash, hives.
• Genitourinary: Increased urination, kidney impairment, increased urinary calcium excretion.

Driving and Operating Machinery

Alfacalcidol generally doesn't directly impair driving or operating machinery. However, dizziness is a possible side effect, so patients should be cautious.

Overdose

High doses of One-Alpha can lead to hypercalcemia, which typically resolves quickly upon stopping the medication. In severe cases, supportive measures like intravenous saline hydration, electrolyte monitoring, and possibly the use of glucocorticosteroids, loop diuretics, bisphosphonates, calcitonin, or hemodialysis may be necessary.

Storage

Store One-Alpha capsules at room temperature (25°C) in an airtight container.