Which adverse drug reactions are known for Carotaben (betacarotene)?/nBackground: A patient with so

Fråga: Which adverse drug reactions are known for Carotaben (betacarotene)? Background: A patient with some type of skin disease has been treated with Roaccutane (isotretinoin) but later switched to treatment with betacarotene. One month after starting betacarotene treatment, she developed abdominal pain and blood in the faeces. The doctor wonders if betacarotene could have caused this reaction.

Sammanfattning: Information regarding the adverse drug reactions due to betacarotene is limited. No literature reports on abdominal pain or blood in faeces due to betacarotene were found with the exception of one poorly documented spontaneous report concerning abdominal pain in SWEDIS. However, due to the temporal relationship and previous reports of gastrointestinal nature, we can not rule out that betacarotene may have caused the reaction in this patient.

Svar: Betacarotene is not an approved drug in Sweden and is available as a food supplement.

Two earlier questions concerning adverse drug reactions due to betacarotene have been answered in Drugline (1, 2). The first document concerned arthralgia which was classified as probably related to betacarotene treatment. The second report concerned increased liver enzymes after using Phenoro (a drug containing betacarotene and cantaxantin) which was registered in Sweden from 1979 to 1987. Although the reaction was attributed to Phenoro, which role betacarotene has played is unknown.

In a new Medline search, we were unable to find any further reports of adverse drug reactions relating to the drug.

A search in SWEDIS (3) covering the period that Phenoro was registered in Sweden revealed 42 reports concerning liver and biliary system (8 reports), eye (30 reports), skin (1 report), gastrointestinal tract (2 reports) and general (1 report). The gastrointestinal tract reactions were abdominal pain and diarrhoea. All the reactions were classified as possibly related to the drug, but the information provided was too limited to allow proper evaluation of the cases. Moreover, since Phenoro also contained another compound, the role that betacarotene has played in these cases is difficult to determine.

In Martindale (4), loose stools, skin colouration (occasionally), bruising and arthralgia (rarely) are mentioned as adverse drug reactions possibly related to betacarotene. Moreover, there are recent reports indicating that betacarotene supplements may increase the risk of lung cancer in smokers, but because of conflicting reports this issue is still inconclusive (4).

We recommend this case be reported to SADRAC (The Swedish Adverse Drug Reactions Advisory Committee).