What kind of medicines should i use to prevent terrible symptoms of allergies in april to june?

AntihistaminesNasal: You can try over the counter non sedating antihistamines like claritidin or Zyrtec And if the nasal congestion is too bad you can also use a steroid nasal spray like Flonase available over the counter or Nasonex (mometasone) by prescription if these do not help consult an allergist

OTC steroid spray: Probably the most effective treatment with fewest side effects is nasal steroid spray such as Nasacort/Flonase. Some of these are now available without a prescription in the US. You need to start it, if you can, 2-3 weeks before the allergy season as it takes couple weeks to become effective. Non-sedating antihistamine pills are also effective: loratadine/cetirizine/fexofenadine.

An antihistamine: and a steroid bases nasal spray, Both are available OTC.

Several choices: For most people antihistamines with or without a decongestant can be enough. The most effective comes in the form of a steroid nasal spray that needs to be used every day during the season. You can also do both and even add eye drops. Many choose to see an allergist for allergy testing and some choose to go with allergy immunotherapy in addition to avoidance and medications.