Propranolol Hydrochloride

β-alanine (BA), being a non-proteinogenic amino acid, is an important constituent of L-carnosine (LC), which is necessary for maintaining the muscle buffering capacity and preventing a loss of muscle mass associated with aging effects. BA is also very important for normal human metabolism due to the formation of a part of pantothenate, which is incorporated into coenzyme A. BA is synthesized in the liver, and its combination with histidine results in the formation of LC, which accumulates in the muscles and brain tissues and has a well-defined physiological role as a good buffer for the pH range of muscles that caused its rapidly increased popularity as ergogenic support to sports performance. The main antioxidant mechanisms of LC include reactive oxygen species (ROS) scavenging and chelation of metal ions. With age, the buffering capacity of muscles also declines due to reduced concentration of LC and sarcopenia. Moreover, LC acts as an antiglycation agent, ultimately reducing the development of degenerative diseases. LC has an anti-inflammatory effect in autoimmune diseases such as osteoarthritis. As histidine is always present in the human body in higher concentrations than BA, humans have to get BA from dietary sources to support the required amount of this critical constituent to supply the necessary amount of LC synthesis. Also, BA has other beneficial effects, such as preventing skin aging and intestinal damage, improving the stress-- fighting capability of the muscle cells, and managing an age-related decline in memory and learning. In this review, the results of a detailed analysis of the role and various beneficial properties of BA and LC from the anti-aging perspective are presented.

Beta-blocker prescriptions for patients with anxiety increased substantially between 2003 and 2018, yet there is no clinical guidance concerning their use. A previous review of propranolol - a beta-blocker - in the treatment of anxiety concluded there was insufficient evidence to support its use. Additional data have been published in the eight years since that review including some evidence for other beta-blockers. We aimed to synthesise all available data on the effectiveness of beta-blockers in the treatment of anxiety disorders in adults.

We searched Medline, Embase, PsycINFO, Web of Science, and Trial Registries (September 2023), including randomised controlled trials (RCT), non-randomised control group comparative studies and cross-over trials reporting self- or clinician-reported anxiety symptoms. Study quality was assessed using Cochrane's Risk of Bias tool, with meta-analyses conducted by comparator group using random-effects models.

Searches produced 3068 records, with 10 studies included, of which five were included in meta-analyses (n = 179). There was no evidence for a beneficial effect of beta-blockers compared with either placebo or benzodiazepines in patients with social phobia or panic disorder with/without agoraphobia (p-value for all meta-analyses ≥0.54).

Many of the included studies had small sample sizes, missing data and high or unclear risk of bias.

Beta-blockers are increasingly prescribed for anxiety, yet there is a lack of robust evidence of effectiveness. There is a need to understand when and why practitioners are using these drugs, and to undertake a large RCT to provide definitive evidence of whether beta-blockers are an effective and safe treatment for anxiety.