Product Information

Registration Status: Active

COLINCTUS 10 MIXTURE 10mg/5ml is approved to be sold in Singapore with effective from 1989-06-22. It is marketed by DRUG HOUSES OF AUSTRALIA PTE LTD, with the registration number of SIN03413P.

This product contains Codeine 10mg/5ml in the form of ELIXIR. It is approved for ORAL use.

This product is manufactured by DRUG HOUSES OF AUSTRALIA PTE LTD in SINGAPORE.

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



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


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.


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.
Apparent volume of distribution = 3-6 L/kg
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.


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.


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