Brand name Vicodin-hydrocodone and acetaminophen (also known as paracetamol or abbreviated as APAP) 5-500 tablets (Abbot Laboratories).

Vicodin is a trademarked brand narcotic analgesic product containing hydrocodone and paracetamol (also known as acetaminophen). Vicodin is used to relieve moderate to severe pain.^[1] It is usually found in tablet form with either the names Vicodin, Vicodin ES, or Vicodin HP imprinted on one side. Analgesics with the same chemical composition and a similar physical appearance are found under many other trade names, including Anexsia, Anolor DH5, Bancap HC, Zydone, Dolacet, Lorcet, Lortab, and Norco. The hydrocodone/paracetamol drug formula is also available under generic brands. The paracetamol in the formula increases the effects of the hydrocodone. Hydrocodone also comes in a combination with ibuprofen, available under the trade name Vicoprofen.

[edit] Ingredients

Vicodin is made as a mixture of hydrocodone and paracetamol. Paracetamol, which is also called acetaminophen, acts as an analgesic/antipyretic. Hydrocodone is a semi-synthetic opioid analgesic.

• Vicodin contains 500 mg paracetamol and 5 mg hydrocodone. Typical dosage is 1-2 tablets as needed, max 8 tablets/day.
• Vicodin ES contains 750 mg paracetamol and 7.5 mg hydrocodone. Typical dosage is 1 tablet as needed, max 5 tablets/day.
• Vicodin HP contains 660 mg paracetamol and 10 mg hydrocodone. Typical dosage is 1 tablet as needed, max 6 tablets/day.

Non-active ingredients included in each pill as well: colloidal silicon dioxide, starch, croscarmellose sodium, dibasic calcium phosphate, magnesium stearate, microcrystalline cellulose, povidone, and stearic acid.^[2]

[edit] Regulation and scheduling

In the United States, Vicodin production is regulated in part by the Controlled Substances Act of 1970. This guarantees that all manufacturing, importing, possession, and distribution of drugs is to be overseen and regulated by the federal government.

In the U.S. Vicodin is a Schedule III drug. Pure codeine and hydrocodone are Schedule II drugs but when compounded with paracetamol or with an NSAID they can become a Schedule III drug. Schedule III drugs are classified by the U.S. government as potentially causing moderate or low physical dependence or a high psychological dependence if misused.

[edit] Ban proposed in the U.S.

This article may need to be updated. Please update this article to reflect recent events or newly available information, and remove this template when finished. Please see the talk page for more information. (October 2009)

On June 30, 2009, a U.S. Food and Drug Administration (FDA) advisory panel voted by a narrow margin to advise the FDA to remove Vicodin and another painkiller, Percocet, from the market because of "a high likelihood of overdose from prescription narcotics and acetaminophen products". The panel cited concerns of liver damage from their acetaminophen component, which is also the main ingredient in commonly-used nonprescription drugs such as Tylenol.^[3] Each year, acetaminophen overdose is linked to about 400 deaths and 42,000 hospitalizations.^[4]

The FDA is not required to follow its advisory committee recommendations, but usually does.^[5]

Hydrocodone, the narcotic component of Vicodin, is still available in Canada as a single drug and marketed under the trade name Hycodan in syrup and tablet forms by Bristol-Myers-Squibb.^[6]

[edit] Manufacture

The principal constituent of Vicodin, hydrocodone, has the same basic structure as morphine but is metabolized by different enzymes. There are three variations of Vicodin, with different amounts of hydrocodone / paracetamol (acetaminophen) in each. Hydrocodone is an intermediate-strength analgesic which has similar effects as morphine, though it should be noted that hydrocodone is less potent than morphine. The tablets are made with less hydrocodone than paracetamol. The theory of using the mix comes from the idea that these drugs alleviate pain using different mechanisms and also that the adverse side effects of each separate drug are reduced by using reduced dosages of both drugs in order to get the same analgesic effect.^[7]

Both hydrocodone and acetaminophen are white crystalline powders, which are then manufactured into tablet form. Manufacturers of hydrocodone (generic or otherwise) include Abbott Laboratories (makers of trademark Vicodin), Amerisource Health Services Corp, Cardinal Health, Drx Pharmaceutical Consultants Inc, Eckerd Corp, Hospira Inc, Knoll Laboratories Div Knoll Pharmaceutical Co, Mallinckrodt Pharm. Quality Care, Pdrx Pharmaceuticals Inc, Physicians Total Care Inc, Rx Pak Div of Mckesson Corp, Sandhills Packaging Inc, and Watson Pharmaceuticals.

[edit] Pharmacokinetics

Besides the activity of hydrocodone and acetaminophen on their own, there is observed a factor of analgesia related to the two substances in tandem which is not altogether understood, but this independent synergy has been observed to be related to the inhibition of prostaglandins. The pharmacokinetics of a mixed drug such as Vicodin depends on the kinetics of the drugs that comprise it.

Hydrocodone: acts at mu opioid receptors.^[8] Hydrocodone is metabolized to hydromorphone by the activity of cytochrome P450 2D6. Cytochrome 3A4 forms the substrate norhydrocodone. Note that this conversion is only somewhat responsible for the effects of hydrocodone.^[9] Cytochromes are haemoprotiens found in the cells of all living organisms and are involved primarily with the electron transport chain producing ATP. Hydrocodone passes through the Blood Brain Barrier because of its modifications, the brain is typically where the analgesic effects are being carried out. Many of the side effects of this drug are caused by the fact that it so readily crosses the BBB. The half-life of hydrocodone is approximately 3.8 hrs.

Paracetamol: the major active metabolites are sulphates and glucuronide conjugates. Its main mode of action is to inhibit the activity of the enzyme cyclooxygenase (COX). COX enzymes are necessary for the production of prostaglandins. Prostaglandins are a form of hormone (although rarely classified as such), which are indicated to be mediators of pain, fever and inflammation. The half-life of paracetamol may be measured either by salivary or plasma counts. Both measurements give a varying half-life between 1 and 4 hours.^[10] Peak levels are reached between 40–60 minutes after ingestion. It has been proposed that paracetamol aids in the reduction of pain by increasing seratonergic neurotransmissions.^[11] Paracetamol is a peripherally acting drug, and hence does not cross the BBB as readily as hydrocodone.^{[citation needed]}

[edit] Indications

Vicodin, like other opioid analgesics, is used to manage pain. It is most commonly prescribed for relief of moderate to moderately severe pain of acute, chronic, or post-operative types. It can also be used to treat severe cough.

[edit] Pregnancy

This drug is classified under pregnancy category C. Although not enough research has been done to deem this drug safe for pregnant women, if the positive effects outweigh the possible negatives, then it can be taken. If taken in the time before delivery, it may give rise to respiratory depression in the baby. Mothers who use any opioids regularly during pregnancy run the risk of their babies being substance dependent and therefore going through withdrawal symptoms after birth. Withdrawal symptoms include: excessive crying, vomiting, irritability, tremors and fever. Nursing mothers should not use this drug as paracetamol is transferred through breast milk and it is unknown if hydrocodone is.^[12]

[edit] Side effects

Side effects for Vicodin are most commonly upset stomach, nausea, and altered mental status (e.g., dizziness, light headedness). Other more rare side effects include allergic reaction, seizures, clammy skin, hallucinations, severe weakness, dizziness, hyperventilation, unconsciousness, jaundice (yellowing of eyes or skin), unusual fatigue, bleeding, bruising, stomach pain^[13], constipation, dry mouth, decreased appetite, muscle twitches, sweating, hot flashes, itching, tinnitus, hearing loss, decreased urination, and altered sex drive. Vicodin also has depressant effects on the central nervous system. However, some of the less mundane effects can be desirable effects that are sought after by some. Those effects include euphoria and drowsiness, as well as slowing of the pulse. Unlike NSAIDs, paracetamol does not cause ulcers. Liver damage can manifest ranging from abdominal pain to outright liver failure, and can necessitate a liver transplant to avoid death. Paracetamol dosages should never exceed 4g a day; this is especially important and may be a smaller number when dealing with mixed drugs like Vicodin. It is imperative that users of this drug follow physician prescribed dosages.

[edit] References

[edit] External links

• U.S. DEA Drug Schedule
• U.S. Federal Regulations