Vorinostat (SAHA) is a pan-histone deacetylase (HDAC) inhibitor (IC50=10 nM) with inhibitory activity against HDAC1/2/3/6/7/11. Vorinostat has antitumor activity, induces cell differentiation, blocks the cell cycle and induces apoptosis.

4-Phenylbutyric acid (Benzenebutyric acid) is a histone deacetylase (HDAC) inhibitor and an endoplasmic reticulum stress (ERS) inhibitor. 4-Phenylbutyric acid can be used to treat urea cycle disorders.

Acefylline (Theophylline-7-acetic acid), a stimulant drug of the xanthine chemical class, acts as an adenosine receptor antagonist. It is combined with diphenhydramine in the pharmaceutical preparation Etanautine to help offset its stimulant effects

Theophylline monohydrate (Quibron) appears to inhibit phosphodiesterase and prostaglandin production, regulate calcium flux and intracellular calcium distribution, and antagonize adenosine. Theophylline monohydrate is a natural alkaloid derivative of xanthine isolated from the plants Camellia sinensis and Coffea arabica. Physiologically, this agent relaxes the bronchial smooth muscle, produces vasodilation (except in cerebral vessels), stimulates the CNS, stimulates the cardiac muscle, induces diuresis, and increases gastric acid secretion; it may also suppress inflammation and improve contractility of the diaphragm.

Valproic Acid (2-Propylpentanoic Acid) is an HDAC inhibitor that inhibits HDAC1 activity, induces HDAC2 degradation, and is orally active. Valproic Acid can be used in epilepsy and bipolar disorder research.