EVERYONE is affected by the stress of modern life; and, ironically, in the quest for respite, uncontrolled self-meditation, in all forms, is practiced, which sometimes leads to serious situations. At times, dental personnel prescribe medications for their patients unnecessarily, an act which, in itself, constitutes drug abuse. While all drugs produce undesirable side effects, cognizance must also be given to the various conditions derived from the use of certain drugs.
Up to 8 grams (one-third of an ounce) of sugar is added to every 2 teaspoons of some liquid forms of medication in order to preserve the product and conceal an unpleasant taste.  
If taken several times a day, the last intake (often at bedtime and perhaps kept in the mouth for a minute or two before being swallowed) will have a rapidly catastrophic  effect on the teeth in the form of decay. Therefore, without quite realising it, cough syrup etc can cause dental caries in persons who do not adhere to the rules of oral health.
Aspirin is probably the most frequently used drug. Indeed, it is widely believed to be capable of preventing chronic heart disease if taken consistently, and also promoted as the best medicine for arthritis.
However, a daily intake of 2 to 3 aspirins can result in as much as 5 milliliters (one teaspoon) of blood being lost in the faeces every 24 hours, due to its erosive effect on the protective mucosal barrier of the stomach.
If this continues for some time without a dietary supplementation of iron, the person may eventually develop iron deficiency anemia, the symptoms of which can include a smooth tongue surface, tenderness in the oral cavity, pain when swallowing, tiredness and shortness of breath.
Hookworm infestation may present identical symptoms. Because the oral symptoms predominate, it is likely that the dentist will be the first to diagnose the problem, especially in postmenopausal women.
Every patient currently on systemic corticosteroid medication should be covered with an extra dose of steroid on the day he visits the dentist. If this is not done, the stressful experience could trigger an adrenal insufficiency syndrome with a sudden fall in blood pressure, leading to severe shock and even death.
It is estimated that the risk of an allergic reaction in asthmatic patients is 5 to 10 times higher than in normal patients. They are especially prone to react allergically if treated with penicillin or aspirin.
Aplastic anemia is a serious and sometimes fatal complication of the use of drugs that can depress the bone marrow, resulting in an arrest of the production of red and white blood cells and platelets. One of the first symptoms in this condition is spontaneous bleeding of the gums, with oral sores in a very pale patient.
Among the drugs known to induce bone marrow depression are chloramphenicol and phenylbutazone, commonly known used to treat typhoid and arthritis, respectively.
Patients suffering from grand mal epilepsy (the type with convulsions) usually take hydantoin sodium. This drug causes the gums to swell, which may ultimately cover most of the crowns of the teeth.  It is advisable that before dental treatment, these persons should have pre-medication with sedatives such as diazepam or oxazepam.
Chlorhexidine is a widely used, very effective disinfectant of the mouth. The recommended concentration routine use is 0.2%. It is well known that Chlorhexidine can cause discoloration of the teeth and tongue, while inducing taste disturbances.
Consequently, as an important participant in the treatment process, the danger of potential drugs must never be underestimated. And the list goes on. So it is important to let your dentist be aware of any medication that you use often. He or she is trained to combat or ameliorate the deleterious side effects, if or when they occur.