Drug Despec: Uses, indications and notes when using

Despec is intended for the temporary treatment of cough, chest tightness and congestion caused by the common cold, flu, allergies, allergic rhinitis (hay fever) or other respiratory conditions (eg: Sinusitis, bronchitis).

Guaifenesin is an expectorant that thins and loosens mucus in the lungs, making it easier to cough up phlegm. Dextromethorphan is a medicine that helps relieve cough. This product also contains a decongestant ingredient, which helps relieve symptoms of nasal congestion. This medicine is not usually used for persistent coughs caused by smoking, asthma, other persistent breathing problems (e.g., emphysema), or coughs with a lot of phlegm.
Children under 12 years old need a doctor's prescription before using these drugs. The products can cause serious side effects. Therefore, to reduce the risk of serious side effects, follow all dosing instructions carefully. Do not drink despec to make the child drowsy. Do not use other cough and cold medicines that may contain similar ingredients.
Other methods can be used to relieve cough and cold symptoms, such as drinking enough water, using a humidifier, or using saline nasal drops.
If you are taking an over-the-counter product, read all directions on the product packaging before taking this medication. Take Dextromethorphan exactly as directed by your doctor.
Use despec by drinking directly, with or without food. Follow the dosing instructions on the product packaging, or take as directed by your doctor. Drink plenty of fluids while you are using this medication unless otherwise directed by your doctor. The fluid will help loosen mucus in the lungs. This medicine can be taken with food for stomach upset.
If you are using Despec liquid, use the dosimeter carefully. The medicine should be shaken well before use if your product is a suspension.
If you are taking tablets, swallow them whole, do not crush them or chew them. Doing so can destroy the long-lasting effects of the medication and increase side effects.

Dosage is determined based on your age, medical condition and response to therapy.
Abuse of this drug can lead to serious harm (e.g., brain damage, seizures, death). Do not increase your dose or take this medication more often than directed by your doctor or directed on the product packaging without your doctor's approval.
If your condition persists for more than 1 week, notify your doctor immediately. Or if the condition worsens or presents with symptoms such as fever, rash, or persistent headache.

There may be signs of dizziness, headache, nausea, nervousness or trouble sleeping. If the condition becomes more serious, contact your doctor immediately.
If you experience serious side effects after taking Despec such as: Mental/mood changes (e.g. Confusion, hallucinations), tremors, weakness or some other rare serious side effects such as: : Fast/slow/irregular heartbeat.
Rarely, serious allergic reactions have occurred after taking Despec.
The above is not a complete list of all possible side effects caused by Despec. Therefore, contact your doctor immediately if you experience any unusual symptoms after taking the medicine.

Before taking Despec, tell your doctor if you are allergic to the drug or any other product. In Despec may contain inactive ingredients so it could cause allergic reactions or other problems.
Before using this medicine, you need to tell your doctor about your medical history, especially of: Breathing problems (asthma, emphysema), diabetes, certain eye problems (glaucoma), heart problems, high blood pressure, kidney problems, an overactive thyroid gland (hyperthyroidism), difficulty urinating (e.g., due to an enlarged prostate).
Taking Despec may make you feel dizzy. Therefore, alcoholic beverages such as wine, beer, etc. should be limited during drug use.
Some Despec liquid products may contain sugar, aspartame and/or alcohol. So use caution if you have diabetes, alcohol or liver disease, phenylketonuria (PKU), or any other condition that requires limiting/avoiding these substances in your daily diet.
Some drug side effects may become more sensitive to older adults, such as: Dizziness, difficulty urinating, fast/irregular heartbeat, trouble sleeping, confusion or mood swings .
Should only use Despec when absolutely necessary during your pregnancy. Talk to your doctor about the risks and benefits of using this medicine.

Despec may interact with some medications, affecting how they work or increasing the risk of serious side effects.
Taking certain MAO inhibitors while using this medicine can cause serious (possibly even fatal) drug interactions. During treatment with Despec, isocarboxazid, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, selegiline or tranylcypromine should be avoided. Most MAO inhibitors are also not recommended for two weeks prior to Despec treatment. Consult your doctor about when to start or stop taking this medicine.
Despec may interact with a number of drugs, including: Beta blockers (e.g. Metoprolol, atenolol), guanethidine, certain inhaled anesthetics (e.g. Halothane), methyldopa, rolapitant, antidepressants depression (eg, Amitriptyline, desipramine).
Guaifenesin is available in both prescription and over-the-counter products. Check the information on the product packaging carefully to make sure that you are not taking more than one medicine that contains the ingredient guaifenesin.
Check the labels on all medicines you are taking (e.g. Cough and Cold Products, diet aids) as they may contain other ingredients that pose a risk of increased heart rate and blood pressure.
This medication may interfere with certain medical tests (including urine 5-HIAA/VMA levels, brain scans for Parkinson's disease), possibly causing false test results.
If signs like fainting or shortness of breath appear after taking Despec, call 911 immediately. Overdose can lead to a number of manifestations such as: agitation, confusion, hallucinations, convulsions.
Use the medicine regularly as directed by your doctor.
Despec medicine should be stored at a temperature of 15-30 degrees Celsius, protected from light and moisture.
Refer to the drug storage instructions on the product packaging.

Reference source: webmd.com