norprolac

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

norprolac is a non-ergot-derived selective dopamine D2 receptor agonist used for the treatment of elevated levels of prolactin or hyperprolactinaemia. Hyperprolalctinaemia is associated with gonadal dysfunction, including infertility and reduced libido, as well as long-term complications such as osteoporosis . Newer dopamine receptor agonists such as quinagolide and Cabergoline are shown to effectively inhibit prolactin secretion with improved efficacy over Bromocriptine. These drugs are effective in patients who are intolerant or resistant to Bromocriptine. norprolac exists as a racemate and its relevant clinical activity is mediated predominantly by the (-) enantiomer. It is typically present in the hydrochloride salt form and is marketed as oral tablets under the brand name Norprolac contained as a racemate. norprolac is currently available in several countries including Canada, but not approved for treatment in the United States.

norprolac achieves long-lasting reduction in prolactin levels in a dose-proportional effect via selectively targeting D2 receptors as an agonist. It potently suppresses both basal and stimulated serum prolactin levels by exerting a strong inhibitory effect on the secretion of the anterior pituitary hormone prolactin.

norprolac
Uses
Dosage
Side Effect
Precautions
Interactions
Uses during Pregnancy
Uses during Breastfeeding
Accute Overdose
Food Interaction
Half Life
Volume of Distribution
Clearance
Interaction With other Medicine
Contradiction
Storage

Trade Name	norprolac
Generic	Quinagolide
Quinagolide Other Names	Quinagolida, Quinagolide, Quinagolidum
Weight	75µg,
Type	Tablet
Formula	C₂₀H₃₃N₃O₃S
Weight	Average: 395.56 Monoisotopic: 395.224263109
Protein binding	Plasma protein binding is reported to be non-specific with an approximate ratio of 90%.
Groups	Approved, Investigational
Therapeutic Class
Manufacturer	Ferring
Available Country	Saudi Arabia, Australia, Netherlands, Portugal, Switzerland,
Last Updated:	September 19, 2023 at 7:00 am

Uses

norprolac is a dopamine D2 receptor agonist used for the treatment of hyperprolactinemia.

Indicated for the treatment of hyperprolactinemia (idiopathic or originating from a prolactin-secreting pituitary microadenoma or macroadenoma).

norprolac is also used to associated treatment for these conditions: Idiopathic Hyperprolactinemia, Idiopathic hyperprolactinemic disorder

How norprolac works

Prolactin secretion from the lactotroph cells present in the anterior pituiatry gland is under tonic inhibitory control mediated by dopaminergic signalling via D2 receptors . norprolac selectively binds to D2 receptors expressed on the surface of lactotroph cells with high affinity which results in reduced adenylyl cyclase activity, reduced intracellular cyclic adenosine monophosphate and inhibited prolactin secretion. It also binds to D1 receptors but with low affinity and little clinical relevance .

Toxicity

Most commonly observed adverse effects are nausea, vomiting, headache, dizziness and fatigue that usually appear in the beginning of initial therapy. Less frequent side effects (1 to 10%) include anorexia, abdominal pain, constipation or diarrhoea, insomnia, oedema, flushing, nasal congestion and hypotension. Orthostatic hypotension may result in faintness or syncope . norprolac demonstrates carcinogenic potential in animal studies but with no known relevance in humans. It is not demonstrated to be embryotoxic or teratogenic, but it is associated with reduced pregnancy rates . Oral LD50 values in mouse, rat and rabbit are 300 mg/kg, 980 mg/kg and 3200 mg/kg, respectively .

Food Interaction

Avoid excessive or chronic alcohol consumption. Alcohol may increase the risk of dizziness, thereby reducing the tolerability of quinagolide.
Take with a light meal or snack. Food reduces gastric irritation.

Volume of Distribution

Approximate volume of distribution is 100L following a single oral admininstration. The parent drug and metabolites is predicted to be extensively distributed in the extravascular compartment with primary target organs being the liver, kidneys, salivary glands and pituitary .

Elimination Route

The absorption of quinagolide is rapid and extensive with 95% of the dose absorbed after oral ingestion, however the absolute bioavailability is low (4 %) due to pre-systemic metabolism. The time to reach peak plasma concentration is 30-60 minutes. Prolactin-lowering effect of quinagolide at recommended therapeutic doses occurs within 2 hours after ingestion reaches a maximum within 4 to 6 hours and is maintained for at least 24 hours .

Half Life

The terminal half-life for parent drug is 11.5 hours following single dose and 17 hours at steady state.

Elimination Route

More than 95% of total dose is excreted as metabolites and the excretion via urine and feces is approximately equal. Renal elimination accounts for 50% of total elimination, where sulfate or glucuronide conjugates, N-desethyl and N,N-didesethyl analogues can be detected in the urine. Unconjugated forms of sulfate or glucuronide conjugates, N-desethyl and N,N-didesethyl analogues are excreted into feces, and fecal elimination accounts for 40% of the total elimination of the drug.