PROMEDYL-B LINCTUS

Product Information

Registration Status: Active

PROMEDYL-B LINCTUS is approved to be sold in Singapore with effective from 1989-05-22. It is marketed by BEACONS PHARMACEUTICALS PTE LTD, with the registration number of SIN02838P.

This product contains Codeine 9mg/5ml,Ephedrine 7.2mg/5ml, and Promethazine 3.6mg/5ml in the form of ELIXIR. It is approved for ORAL use.

This product is manufactured by BEACONS PHARMACEUTICALS PTE LTD in SINGAPORE.

It is a Pharmacy Only Medicine that can be obtained from a pharmacist at a retail pharmacy.

Codeine
Ephedrine
Promethazine

Description

An opioid analgesic related to morphine but with less potent analgesic properties and mild sedative effects. It also acts centrally to suppress cough.

Indication

For treatment and management of pain (systemic). It is also used as an antidiarrheal and as a cough suppressant.

Mechanism of Action

Opiate receptors are coupled with G-protein receptors and function as both positive and negative regulators of synaptic transmission via G-proteins that activate effector proteins. Binding of the opiate stimulates the exchange of GTP for GDP on the G-protein complex. As the effector system is adenylate cyclase and cAMP located at the inner surface of the plasma membrane, opioids decrease intracellular cAMP by inhibiting adenylate cyclase. Subsequently, the release of nociceptive neurotransmitters such as substance P, GABA, dopamine, acetylcholine and noradrenaline is inhibited. Opioids also inhibit the release of vasopressin, somatostatin, insulin and glucagon. Codeine's analgesic activity is, most likely, due to its conversion to morphine. Opioids close N-type voltage-operated calcium channels (OP2-receptor agonist) and open calcium-dependent inwardly rectifying potassium channels (OP3 and OP1 receptor agonist). This results in hyperpolarization and reduced neuronal excitability.

Pharmacokinetics

Absorption
Well absorbed following oral administration with a bioavailability of approximately 90%. Maximum plasma concentration occurs 60 minutes post-administration. Food does not effect the rate or extent of absorption of codeine.
Distribution
Apparent volume of distribution = 3-6 L/kg
Metabolism
Hepatic. Codeine is a prodrug, itself inactive, but demethylated to the active morphine by the liver enzyme CYP2D6 to morphine. 70-80% of the dose undergoes glucuronidation to form codeine-6-glucuronide. This process is mediated by UDP-glucuronosyltransferase UGT2B7 and UGT2B4. 5-10% of the dose undergoes O-demethylation to morphine and 10% undergoes N-demethylation to form norcodeine. CYP2D6 mediates the biotransformation to morphine. CYP3A4 is the enzyme that mediates the conversion to norcodiene. Morphine and norcodeine are further metabolized and undergo glucuronidation. The glucuronide metabolites of morphine are morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G). Both morphine and morphine-6-glucuronide are active and have analgesic activity. Norcodiene and M3G do not have any analgesic properties.
Elimination

Toxicity

Respiratory depression, sedation and miosis and common symptoms of overdose. Other symptoms include nausea, vomiting, skeletal muscle flaccidity, bradycardia, hypotension, and cool, clammy skin. Apnea and death may ensue.

Active Ingredient/Synonyms

(−)-Codeine | (5alpha,6alpha)-7,8-Didehydro-4,5-epoxy-3-methoxy-17-methylmorphinan-6-ol | (5α,6α)-7,8-didehydro-4,5-epoxy-3-methoxy-17-methylmorphinan-6-ol | 3-Methylmorphin | 3-methylmorphine | 7,8-didehydro-4,5alpha-epoxy-3-methoxy-17-methylmorphinan-6alpha-ol | 7,8-didehydro-4,5α-epoxy-3-methoxy-17-methylmorphinan-6α-ol | Codein | Codeína | Codéine | Codeine anhydrous | Codeine polistirex | Codeinum | L-Codeine | Methylmorphine | morphine 3-methyl ether | Morphine monomethyl ether | morphine monomethyl ether | morphine-3-methyl ether | O(3)-methylmorphine | Codeine |


Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.


Description

An alpha- and beta-adrenergic agonist that may also enhance release of norepinephrine. It has been used in the treatment of several disorders including asthma, heart failure, rhinitis, and urinary incontinence, and for its central nervous system stimulatory effects in the treatment of narcolepsy and depression. It has become less extensively used with the advent of more selective agonists.

Indication

Ephedrine commonly used as a stimulant, appetite suppressant, concentration aid, decongestant, and to treat hypotension associated with anaesthesia.

Mechanism of Action

Ephedrine is a sympathomimetic amine - that is, its principal mechanism of action relies on its direct and indirect actions on the adrenergic receptor system, which is part of the sympathetic nervous system. Ephedrine increases post-synaptic noradrenergic receptor activity by (weakly) directly activating post-synaptic α-receptors and β-receptors, but the bulk of its effect comes from the pre-synaptic neuron being unable to distinguish between real adrenaline or noradrenaline from ephedrine. The ephedrine, mixed with noradrenaline, is transported through the noradrenaline reuptake complex and packaged (along with real noradrenaline) into vesicles that reside at the terminal button of a nerve cell. Ephedrine's action as an agonist at most major noradrenaline receptors and its ability to increase the release of both dopamine and to a lesser extent, serotonin by the same mechanism is presumed to have a major role in its mechanism of action.

Pharmacokinetics

Absorption
85%
Distribution
Metabolism
Elimination

Toxicity

Cardiovascular: tachycardia, cardiac arrhythmias, angina pectoris, vasoconstriction with hypertension

Active Ingredient/Synonyms

(-)-Ephedrine | (1R,2S)-1-Phenyl-1-hydroxy-2-methylaminopropane | L-Ephedrine | L-erythro-2-(Methylamino)-1-phenylpropan-1-ol | L(−)-ephedrine | Ephedrine |


Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.


Description

A phenothiazine derivative with histamine H1-blocking, antimuscarinic, and sedative properties. It is used as an antiallergic, in pruritus, for motion sickness and sedation, and also in animals. [PubChem]

Indication

For the treatment of allergic disorders, and nausea/vomiting.

Mechanism of Action

Like other H1-antagonists, promethazine competes with free histamine for binding at H1-receptor sites in the GI tract, uterus, large blood vessels, and bronchial muscle. The relief of nausea appears to be related to central anticholinergic actions and may implicate activity on the medullary chemoreceptor trigger zone.

Pharmacokinetics

Absorption
On average, 88% of a promethazine dose is absorbed after oral administration; however, the absolute bioavailability is only 25% because of first-pass clearance.
Distribution
Metabolism
Hepatic
Elimination

Toxicity

Symptoms of overdose include mild depression of the central nervous system and cardiovascular system to profound hypotension, respiratory depression, unconsciousness, and sudden death. Other reported reactions include hyperreflexia, hypertonia, ataxia, athetosis, and extensor-plantar reflexes (Babinski reflex). LD50=55mg/kg (I.V. in mice)

Active Ingredient/Synonyms

(2-dimethylamino-2-methyl)ethyl-N-dibenzoparathiazine | 10-(2-Dimethylaminopropyl)phenothiazine | 10-[2-(dimethylamino)Propyl]phenothiazine | N-(2'-dimethylamino-2'-Methyl)ethylphenothiazine | N,N,alpha-Trimethyl-10H-phenothiazine-10-ethanamine | N,N,α-trimethyl-10H-phenothiazine-10-ethanamine | Proazamine | Prometazina | Promethazine | Promethazinum | Promethazine |


Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.

References

  1. Health Science Authority of Singapore - Reclassified POM
  2. Drugbank