Myalfa

Myalfa Uses, Dosage, Side Effects, Food Interaction and all others data.

Myalfa is a precursor of the active calcitriol. It does not require renal hydroxylation but requires 25-hydroxylation in the liver for conversion to calcitriol.

Myalfa works to increase serum levels of calcium by stimulating intestinal calcium absorption, reabsorption of calcium from bone, and possibly the renal reabsorption of calcium. It also modestly promotes intestinal phosphorus absorption. In patients with renal failure, alfacalcidol increased intestinal calcium and phosphorus absorption in a dose-related manner. This increase in calcium and phosphorus levels occurs within three days following drug administration: this effect was reversed within three days of drug discontinuation. In patients with chronic renal failure, serum calcium levels were elevated while parathyroid hormone and alkaline phosphatase levels returned to normal levels within five days following alfacalcidol administration. Since alfacalcidol suppresses parathyroid hormone, a reduction in parathyroid hormone levels is achieved more rapidly in patients on intermittent intravenous therapy, with significant reductions occurring within three months of therapy. In patients receiving daily oral therapy of alfacalcidol, the time it takes alfacalcidol to normalize plasma calcium levels may be up to several months, possibly reflecting calcium being utilized for bone mineralization. In patients with nutritional osteomalacia, alfacalcidol increased calcium absorption with six hours of oral administration and the effects peaked at 24 hours.

Trade Name Myalfa
Generic Alfacalcidol
Alfacalcidol Other Names Alfacalcidol, Alfacalcidolum
Weight 0.5mcg
Type Tablet
Formula C27H44O2
Weight Average: 400.6371
Monoisotopic: 400.334130652
Protein binding

The active metabolite of alfacalcidol, 1,25-dihydroxyvitamin D, is transported to tissues via globulin, a specific transport protein.

Groups Approved, Nutraceutical
Therapeutic Class Vitamin in bone formation, Vitamin-D preparations
Manufacturer Welmark Pharmaceuticals
Available Country Pakistan
Last Updated: September 19, 2023 at 7:00 am
Myalfa
Myalfa

Uses

Myalfa is used for:

  • It is used to increase the amount of vitamin D in your body. This often increases calcium levels as well which can help in treatment of certain illnesses.
  • In general this drug is used to treat diseases where the amount of calcium and phosphate (which is controlled by the level of vitamin D) in your body needs changing.
  • Benefits of being on this drug can include control of the levels of calcium and phosphate in your body.
  • Treat and prevent bone conditions that are caused by kidney failure (osteodystrophy)
  • Treat illnesses and abnormalities affecting the parathyroid glands which make a substance called the parathyroid hormone.
  • Correct low levels of calcium in the blood of newborn babies (hypocalcaemia)
  • Treat the softening and deformity of the bones due to lack of calcium (rickets or osteomalacia)

Myalfa is also used to associated treatment for these conditions: Hypocalcemia, Hypophosphatemic Rickets, Hypovitaminosis D, Nutritional Rickets, Osteodystrophy, Osteomalacia, Secondary Hyperparathyroidism (SHPT), Hypophosphatemic osteomalacia

How Myalfa works

In conditions like chronic renal failure, renal bone disease, hypoparathyroidism, and vitamin D dependent rickets, the kidneys' capacity for 1α-hydroxylation is impaired, leading to reduced production of endogenous 1,25-dihydroxyvitamin D and aberrated mineral metabolism. As an active and potent analog of vitamin D, alfacalcidol works to restore the functions and activities of endogenous 1,25-dihydroxyvitamin D.

Dosage

Myalfa dosage

Adults: The usual starting dose is 1 microgram each day. People usually take between 1 and 3 micrograms each day. Most people take between 0.25 and 1 microgram each day once the blood test results show the medicine is working.

If you have very low levels of calcium in your blood, your doctor may prescribe between 3 and 5 microgram each day. Your doctor may prescribe another medicine called a calcium supplement to take as well as Myalfa. This will help to keep the right amount of calcium level in your blood.

Elderly: The usual starting dose is 0.5 microgram each day.

Children:

  • Newborn and premature babies: The usual starting dose is 0.05 to 0.1 microgram per kilogram of body weight each day. If the level of calcium in their blood is very low, up to 2 micrograms per kilogram of body weight may be needed each day. A dose of 0.1 microgram per kilogram body weight each day is used to stop low blood calcium levels in premature babies.
  • Children weighing less than 20 kilograms: The usual starting dose is 0.05 microgram per kilogram body weight each day.
  • Children weighing more than 20 kilograms: The usual starting dose is 1 microgram each day.

Side Effects

Anorexia, nausea, vomiting, diarrhoea, lassitude, polyuria, sweating, headache, thirst, vertigo, pruritus, rash, urticaria. Hypercalcaemia, hypercalciuria and ectopic calcification.

In case of renal impairment, hyperphosphataemia. In hypercalcaemic dialysis patients, possibility of calcium influx from the dialysate should be considered.

Toxicity

There is a discrepancy across a number of reported LD50 values for alfacalcidol, which can be attributed to differences in the procedures used in laboratories. Oral LD50 in mice ranges from 440 to 490 mcg/kg. Intravenous in mice was 290 mcg/kg; however, another source presented 56 mcg/kg in female mice and 71 mcg/kg in male mice. Oral LD50 in rats ranges from 340 to 720 mcg/kg.

In case of an acute accidental overdose following oral administration, emesis or gastric lavage can be induced to prevent further drug absorption. Mineral oil may be used to promote fecal drug elimination in instances where the drug was already absorbed in the stomach.

Myalfa overdose can lead to hypercalcemia, hypercalciuria, and hyperphosphatemia. Similarly, a high intake of calcium and phosphate concurrently with a therapeutic dose of alfacalcidol can result in those conditions. Hypercalcemia most commonly presents with headache, weakness, hypertension, somnolence, dizziness, sweating, anorexia, nausea, vomiting, diarrhea, constipation, polyuria, polydipsia and muscle and bone pain, and metallic taste. Hypercalcemia should be responded to with discontinuation of alfacalcidol, a low calcium diet and withdrawal of calcium supplements. Prolonged hypercalcemia can lead to nephrocalcinosis, nephrolithiasis, and reduced kidney function. In cases of severe hypercalcemia, general supportive measures are recommended, which may include forced diuresis and close monitoring of renal function, electrolytes, and electrocardiographs. Monitoring for abnormalities is especially critical in patients receiving digitalis glycosides. Management with glucocorticosteroids, loop diuretics, bisphosphonates, and calcitonin, as well as hemodialysis with low calcium content, may be considered.

Precaution

Pregnancy, lactation, renal impairment, infants, elderly. Monitor serum levels of calcium in patients with renal failure. Caution in hypercalciuria in those with history of renal calculi. Avoid in patients with hypersensitivity to inj. containing propylene glycol.

Interaction

Thiazides may increase the risk of hypercalcaemia. Some antiepileptics e.g. carbamazepine, phenobarbital, phenytoin and primidone may increase vitamin D requirements. Rifampicin, isoniazid and corticosteroids may reduce the efficacy of vitamin D.

Food Interaction

  • Take with or without food. Food does not affect the bioavailability.

Elimination Route

Myalfa is absorbed passively and almost completely in the small intestine.

Half Life

The half-life of alfacalcidol ranges from three to four hours.

Pregnancy & Breastfeeding use

FDA has not yet classified the drug into a specified pregnancy category.

Contraindication

Hypercalcaemia, metastatic calcification, hyperphosphataemia (except when occurring with hypoparathyroidism), hypermagnesaemia.

Innovators Monograph

You find simplified version here Myalfa

Myalfa contains Alfacalcidol see full prescribing information from innovator Myalfa Monograph, Myalfa MSDS, Myalfa FDA label

FAQ

What is Myalfa used for?

Myalfa is an analogue of vitamin D used for supplementation in humans and as a poultry feed additive. Myalfa is a vitamin D supplement used to treat deficiency in conditions including hypocalcemia (low blood calcium levels), rickets (bone weakness), and others.

What is Myalfa used for?

Myalfa can cause some serious side effects and can lead to some serious health problems. Talk with your doctor if you are having any serious problems.

How does Myalfa work?

Myalfa works to increase serum levels of calcium by stimulating intestinal calcium absorption, reabsorption of calcium from bone, and possibly the renal reabsorption of calcium. It also modestly promotes intestinal phosphorus absorption.

What are the common side effects of Myalfa?

Some of the common side effects of Myalfa are:

  • Itching.
  • Rash.
  • Abdominal pain.
  • Headache.
  • Drowsiness.
  • Constipation.
  • Nausea.
  • Vomiting.

Is Myalfa safe during pregnancy?

There is a limited amount of data from the use of Myalfa in pregnant women. Studies in animals have shown reproductive toxicity at high doses. Therefore, One-Alpha is not recommended during pregnancy and in women of child-bearing potential not using contraception.

Is Myalfa safe during breastfeeding?

Myalfa can pass into the breast milk. If Myalfa is used during breastfeeding, please monitor the serum calcium levels of the mother and the infant.

Can I drive after taking Myalfa?

Avoid driving if you feel dizzy after taking Myalfa.

When is the best time to take Myalfa?

You don't have to take all your medication at breakfast time. You can split your Myalfa (and calcium tablets, if taking) over the day. Many people find this helps to prevent calcium levels swinging and keeps them much more stable. Calcium should always be taken with meals.

How many time can I take Myalfa daily?

It is usually taken as one dose a day.

How much Myalfa can I take daily?

The daily dose of One-Alpha may be increased by increments of 0.25 - 0.5 microgram. When the dose is stabilised, measurements may be taken every 2 - 4 weeks. Most adult patients respond to doses between 1 and 3 micrograms per day.

How long does Myalfa take to work?

In patients with nutritional osteomalacia, Myalfa increased calcium absorption with six hours of oral administration and the effects peaked at 24 hours.

How long does Myalfa stay in my system?

The half-life of Myalfa ranges from three to four hours.

Can I take Myalfa for a long time?

Treatment with Myalfa may be for short periods of time (such as in preparation for surgery), or could be long-term.

Who should not take Myalfa?

Contraindicated in patients with high blood calcium, phosphate, and magnesium and known hypersensitivity.

What happens if I overdose of Myalfa?

Myalfa overdose can have severe or life-threatening consequences. Nausea, lack of appetite, thirst, urinating more or less than normal, body aches, weakness, confusion, or erratic heartbeats are all potential opioid signs.

What happens if I stop taking Myalfa ?

Do not stop taking Myalfa or change the dose without first checking with your doctor. Stopping suddenly can lead in a rapid fall in blood calcium levels. Your doctor will tell you the best way to slowly reduce the amount of Myalfa you are taking before stopping completely.

Can Myalfa affects my heart ?

It showed that Myalfa use, when compared to usual care, is not associated with decreased cardiovascular events.

Can Myalfa affect my kidneys?

Early administration of Myalfa can safely and beneficially alter the natural course of renal bone disease in patients with mild to moderate renal failure.

*** Taking medicines without doctor's advice can cause long-term problems.
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