This is just mere hypothetical speculation that spread like wildfire over the net, so now everyone thinks it's fact. They are not the same chemical compounds.
wrong
"Benadryl is sold as an anti-histimine in the United States, and/or a sleep aid elsewhere in the world. However, Beta receptors are embedded in the cell's outer phospholipid membrane. The stability of the membrane has a lot to do with the proper function of the receptors. Methylation of the phospholipids is stimulated by the binding of beta agonists to their receptors. Methylated phospholipids are foreign to the body, and when the body recognizes them as foreign, it breaks them down with phospholipase A2. This changes the structure of the outer membrane which results in desensitizaton of the beta receptors. On the other hand, agents that inhibit phospholipase A2 slow desensitization.
Cationic ampiphylic drugs are known for their ability to inhibit phospholipase A2. Benadryl (diphenhydramine) is a cationic ampiphylic drug.
Ergo, Benadryl slows desensitization of Beta receptors (i.e. Upgrades them) by inhibiting phospholipase A2, which is the enzyme that breaks down methylated phospholipids, and this action in turn keeps the phospholipid membrane stable, and thus keeps the receptors functioning properly.
Reference:
Prog Clin Biol Res. 1981;63:383-8.
Phospholipid methylation: a possible mechanism of signal transduction across biomembranes.
Hirata F, Tallman JF, Henneberry RC, Mallorga P, Strittmatter WJ, Axelrod J"
