Hi Sophie Welcome to HCM, First of all i would like to say that your concern for taking both the drugs have any interaction is absolutely right. I must appreciate your awareness regarding interaction of medicines and asking HCM for help. Only few people have such awareness. Now let me help you out straightly.... From my clinical experience, you can continue with the ear drop BUT It is NOT OK to take Amoxycillin and OCP together as it might affect the OCP pill efficacy leading to pregnancy and better NOT to rely on OCP alone from starting of amoxycillin to approx10 days after stopping it irrespective of pill free weeks. Thats it. Now, after reading this, i hope you might want me to explain my words. So, please allow me to explain and here it goes --- OCP depends on normal bacterial flora for its effectiveness and amoxycillin is going to decrease it which may lead to failure of OCP. So, what to do ??? I as an ENT surgeon, do prescribe amoxycillin for chest infection but with precaution. Precaution means , advising barrier method of contraception such as condom during and till 10 days of stopping amoxycillin. It is just for giving time for normal bacterial flora to re grow so that OCP efficacy regains. Also taking pre or pro biotics combination is a good idea and many antibiotics now a days comes along with it. I can not mention drug name as not allowed by HCM In summary - (1) Do not take amoxycillin and OCP together (2) If you have to take , then use condoms for precautions + or - pre/pro biotics for at least 10 days after stopping it. The answer is based on my day to day clinical practice and you may be better helped by your local doctor after examination. With this i sincerely hope that i could help you out with the answer you wanted. I wish you a very very early recovery and wish you a very healthy and happy life. Regards NOTE: I have noticed that the answer is not displayed after i have sent it to you. So, i am re sending it so that you do not miss it. If it appears twice, please forgive me.