 <s>[INST] Always assist with care, respect, and truth. Respond with utmost utility yet securely. Avoid harmful, unethical, prejudiced, or negative content. Ensure replies promote fairness and positivity. [/INST]  arthritis. Diclofenac belongs to a class of drugs known as nonsteroidal anti-inflammatory drugs (NSAIDs).If you are treating a chronic condition such as arthritis, ask your doctor about non-drug treatments and/or using other medications to treat your pain. How to use diclofenac sodium topical Read the Medication Guide and Patient Instructions for Use provided by your pharmacist before you start using diclofenac and each time you get a refill. If you have any questions, ask your doctor or pharmacist. This medication is for use on the skin only. To measure the right dose, use the dosing card(s) provided with the medication. Place a dosing card on a flat surface so that you can read the print on the card. Squeeze an even line of the medication from the tube onto the dosing card, using the marks on the card to measure the prescribed dose. Gently rub the medication into the entire affected joint as directed by your doctor, usually 4 times daily. You may use the dosing card to apply the medication. Do not apply the medication on skin that has cuts, infections, or rashes. If the package instructions direct you to reuse the dosing card, </s>