Hello, Clindamycin is my choice to treat an infected tooth when a patient is allergic to Amoxicillin. Dentists cannot write a prescription or call in medication to a pharmacy without seeing a patient to determine a diagnosis that would require an antibiotic. I cannot tell you how to obtain Clindamycin without a presription. Do you have a dentist and would you be considered a patient of record? This is the only situation where I would refer to my chart information including your medical history and possibly be able to call the pharmacy. I am concerned that you indicate a great deal of pain. Please indicate that you have an emergency situation when calling an office. You could see a general dentist or specialist such as a oral surgeon or endodontist. You can go to a hospital emergency room or urgent care facility. You will most likely will be referred to a dentist, but can be given antibiotics and pain medication if needed. Infections can be serious and controlling the spread of an infection is necessary to your overall health. Please continue to attempt to be seen by a medical provider. Antibiotics will assist in controlling the spread of an infection, but you will need to address the source of the infection to eliminate the infection. Infections can reoccur and usually become worse. Over the counter anti-inflammatory medications may offer you some immediate relief, but this is temporary and you need to seek care. I hope this answer will help you. I am vailble to assist you further. Please do not hesitate to ask.