You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Antibiotics

Context:
Interactions between alcohol and certain antibiotics may occur and may cause side-effects and decreased effectiveness of antibiotic therapy. While moderate alcohol consumption is unlikely to interfere with many common antibiotics, there are specific types of antibiotics with which alcohol consumption may cause serious side-effects. Therefore, potential risks of side-effects and effectiveness depend on the type of antibiotic administered. Despite the lack of a categorical counterindication, the belief that alcohol and antibiotics should never be mixed is widespread.

Question:
What can alcohol and certain antibiotics cause?

decreased effectiveness of antibiotic therapy