Medicines and liver impairment: what changes and why

The liver is the main site where many medicines are broken down and prepared for removal. In healthy people that process is fast and predictable. In liver disease it may slow, so the same dose produces higher or longer-lasting levels, or in some cases fail to convert a medicine into its active form, so it works less well than expected.

The NHS Specialist Pharmacy Service summarises the consequences as risk of hepatotoxicity, increased side effects and reduced therapeutic effects. It is also important to separate liver disease from liver dysfunction and from drug-induced liver injury, because each calls for different management.

In cirrhosis the Child-Pugh score is used to estimate the severity of liver disease, and drug manufacturers use it to recommend dose adjustments in product information. The score draws on clinical features and blood results, so it is calculated by the clinical team rather than by the patient.

Pharmacy guidance asks professionals to gather recent liver blood test results, the Child-Pugh score where cirrhosis is present, and imaging results. It also asks whether the condition is acute or chronic, whether a specialist is involved and whether the person has had a transplant. A medicine that is acceptable in stable, mild disease may be unsuitable in decompensated cirrhosis.

The Specialist Pharmacy Service lists a structured set of questions for medicines advice in liver impairment. Knowing them helps you prepare for a medicine conversation.

• Patient factors such as age, weight, other conditions including heart failure or kidney problems, alcohol use and metabolic risk.

• The type and course of liver disease, and whether a specialist or transplant team is involved.

• Current severity, from recent blood tests, imaging and any Child-Pugh score.

• Every medicine used, including non-prescription products, supplements, herbal products and recent short-term courses.

• Whether the case is complex enough for specialist referral.

Paracetamol is widely used, and the NHS says most adults can take it, but it also states that it is unsuitable for people with kidney or liver conditions and for those who are alcohol-dependent or binge drink. Taking more than the packet allows can sometimes damage the liver, and the NHS advises contacting NHS 111 if you have taken too much, bringing the packaging.

The NHS also warns against taking paracetamol with other medicines that contain it, such as cold and flu remedies. In liver disease the margin for error can be smaller, so keep to what a clinician has said is acceptable for you rather than the general packet dose.

Anti-inflammatory painkillers have their own problems; NHS ibuprofen guidance lists liver conditions among the reasons it may be unsuitable. A pharmacist or specialist should recommend pain relief for you individually.

For alcohol-related liver disease the NHS says the aim of treatment is usually to help the person stop drinking completely, using talking therapies, medicines to support abstinence or reduce cravings, and support groups. It warns that stopping suddenly can be very dangerous for someone who drinks heavily, so medical help should be sought before trying to stop.

Alcohol also changes how medicines behave. The NHS advises reducing alcohol while taking anti-inflammatory painkillers, and heavy alcohol use is one of the factors a prescriber asks about when assessing liver risk.

Herbal and supplement products can contribute to liver injury, and the Specialist Pharmacy Service includes them in the list of things prescribers must ask about. They are not subject to the same testing as licensed medicines. A product described as natural or detoxifying still has an ingredient list that can be checked by a pharmacist against your condition.

If you notice yellowing of the skin or eyes, itching, nausea or unusual tiredness after starting a new product, stop and seek advice quickly, as these can be signs of liver trouble.

Pharmacy guidance lists fever with chills, shortness of breath, vomiting blood, tarry stools and mental confusion as red flags that indicate advanced liver disease and require urgent referral. Seek emergency care through 999 or A&E for vomiting blood, black stools or sudden confusion.