There are many different kinds of respiratory infections, as "respiratory infection" is a generic term for all illnesses of the respiratory system. This system, responsible for breathing, includes the mouth, nose, throat, airways and lungs. Respiratory infections range from the common cold to influenza (the flu), tonsillitis, laryngitis, sinusitis, bronchitis and pneumonia.
Depending on what type of respiratory infection you have there are different kinds of medications you can take. Most respiratory infections are viral and will clear up on their own after a week or two. Prescription medications such as antibiotics are not effective for viral infections, but there are medications you can take to help alleviate the symptoms while you're waiting for the illness to subside.
For a stuffy nose you can take a decongestant or use saline drops. For a runny nose take an antihistamine. For a cough you can take an antitussive (cough suppressant) or an expectorant to help loosen up the mucous so you can cough it up. For fever, headaches and muscle aches you can take anti-inflammatory medications, such as acetaminophen, ibuprofen or naproxen. Be aware that many nonprescription "multi-symptom" medications include anti-inflammatories in them, so don't take additional anti-inflammatories if you're using one of these products.
There are also some nonmedicinal treatments that may help with your symptoms. Rest, drink lots of fluids and inhale warm, moist air from a humidifier or a hot shower. For a sore throat, gargle with warm saline or use throat lozenges. Echinacea, vitamin C and zinc salts are popular treatments to ward off and prevent infections, although they're not proven as effective.
If you have any of the following symptoms, see your doctor to find out whether your infection is bacterial and you need to take antibiotics: fever above 102 degrees Fahrenheit (38.9 degrees Celsius), chest pain, difficulty breathing, wheezing, skin rash, worsening sore throat or cough that becomes painful, severe headache, yellow or white spots on your throat or tonsils, blue skin, lips or fingernails, or mental confusion.