Taking 3 tablets of Avil (Pheniramine Maleate 25mg) daily is a relatively high dose and may cause side effects such as discomfort, vomiting, and headache, which you have experienced.

Here’s what you should do:

• Stop taking the medication temporarily until you consult a doctor.
• Contact your doctor promptly to discuss these side effects and review your allergy treatment. Your doctor may adjust the dose or suggest an alternative.
• Avoid self-medicating or increasing the dose without medical advice.
• Stay hydrated and rest until you can see your doctor.

If you experience severe symptoms such as difficulty breathing, swelling, or persistent vomiting, seek emergency medical care immediately. Your symptoms suggest that the current dose may not be suitable, so professional evaluation is important for safe allergy management.To narrow down potential causes, we will need some more information.Please tell me your age and gender, so I can better understand your situation. I'm sorry to hear that you experienced discomfort and vomiting last night, followed by a headache and also took 3 Avil daily for allergy.