G) Hypertension: It is one of the major risk factors for atherothrombosis especially stroke. At present, the incidence of hypertension is continuously increasing. Complications such as stroke are significantly reduced if blood pressure is controllable. Aspirin therapy as primary prevention is successfully introduced in high-risk diabetic patients [22].
H) In vitro fertilization (IVF): Low-dose aspirin may improve the clinical pregnancy rate in IVF. Aspirin can effectively inhibit platelet aggregation the mechanism is through selective acetylation of COX a serine hydroxyl, irreversible inhibition of the cyclooxygenase (COX) enzyme, reducing the activity of thromboxane A2 (TXA2) and prostaglandin synthesis (PGs), inflammatory reaction, thus inhibiting platelet activity, and preventing the formation of blood clots, as well as reducing resistance in the blood vessels and increasing tissue perfusion [23].
I) Niacin-induced flushing: It is described by redness and warmth because of the vasodilation of dermal blood vessels and it is associated with a sensation of tingling and burning.
It appears to be likely that niacin-induced flushing is enhanced by prostaglandins produced initially by bone marrow-derived cells such as platelets and dendritic cells, perhaps contributing to subsequent induction of COX-2-dependent lipids by dermal or epidermal cells. During chronic drug administration, niacin-induced flushing and prostaglandin release are subject to tachyphylaxis within seven days. So we can decrease the risk of niacin-induced flushing by pretreatment with aspirin [24].
2.4 Propranolol
Propranolol is a nonselective β -blocker. If β receptor sites are blocked by propranolol, the inotropic, chronotropic, and vasodilator responses to β-adrenergic stimulation are decreased proportionately. However, propranolol should be stopped gradually, if it stopped suddenly may cause chest pain or heart attack in some patients [25]. Off label uses of propranolol:
A) Anxiety: Propranolol now considers as a first-line pharmacological treatment for anxiety disorders and has probably contributed to a step by step declining consideration for the specialist as a potential treatment of anxiety-related conditions. However, propranolol use in anxiety due to its ability to reduce some peripheral symptoms of anxiety, such as tachycardia and sweating [26].
B) Post-burn hypermetabolic response: The burn-induced stress response stimulates the secretion of endogenous catecholamines such as dopamine, norepinephrine, and epinephrine, which are believed to be the main mediators of hypermetabolism after severe burns.
Overproduction of catecholamines induces a hyperdynamic circulation, enhance protein catabolism in skeletal muscle, and augments energy expenditure. Medications that prevent the action of catecholamine on the receptor site such as propranolol is effective at reducing the risk of catecholamine-induced sequelae after severe burns. Propranolol, a non-selective β blocker has been studied extensively and shown promise result for decrease the post-burn hypermetabolic response [27].
C) Gastrointestinal hemorrhage: A meta-analysis study of 1859 patients were included in 20 trials, 931 in the propranolol groups, and 928 as controls observed the beneficial effect of propranolol on both first and recurrent gastrointestinal hemorrhage. The average rate of gastrointestinal hemorrhage was 28% in patients treated with propranolol, but 43% in controls, suggesting that this interventional therapy is highly effective on prevention of upper gastrointestinal tract bleeding also the study observed the effect of propranolol on mortality rate, the average mortality was 20% in patients receiving with propranolol, but 27% in controls [28].
D) Tetralogy of Fallot: It’s a type of heart defect present at birth that leads to episodic central cyanosis due to total occlusion of right ventricle outflow in a patient with congenital heart disease.
Propranolol by its blocking beta-receptor effect on the heart which will lead to a reduction in cardiac contractility may decrease infundibular obstruction of right ventricular outflow. However, propranolol dose for tetralogy of Fallot is 0.1 mg/kg slow IV push and may be repeated in 15 minutes. When used chronically, have the beneficial effect of stabilizing peripheral vascular reactivity [29].
E) Thyroid storm: A thyroid storm is a deadly form of hyperthyroidism associated with untreated hyperthyroidism. 1-2 mg of propranolol can be used intravenously in the treatment of thyroid storm also it can be used orally usually begins at 20–120 mg per dose, or 160–320 mg/day in divided doses, the dose should be increased gradually until symptoms are controlled [30]. Propranolol can relieve the adrenergic symptoms of hyperthyroidism such as tremor, palpitations, heat intolerance, and nervousness. However, propranolol is widely used for thyroid storm because it can block the conversion of T4 to T3 and has a more direct effect on hypermetabolism [31].
Source: https://www.drugpatentwatch.com/blog/common-drugs-with-effective-off-label-uses/
