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.

Valproic acid sodium salt (Sodium Valproate) is the sodium salt form of valproic acid with anti-epileptic activity. Valproic acid sodium salt is converted into its active form, valproate ion, in blood. Although the mechanism of action remains to be elucidated, Valproic acid sodium salt increases concentrations of gamma-aminobutyric acid (GABA) in the brain, probably due to inhibition of the enzymes responsible for the catabolism of GABA. This potentiates the synaptic actions of GABA. Valproic acid sodium salt may also affect potassium channels, thereby creating a direct membrane-stabilizing effect.

Panobinostat (NVP-LBH589) is a broad-spectrum HDAC inhibitor (IC50=5 nM) with oral activity and non-selectivity. Panobinostat has antitumor activity and induces apoptosis and autophagy.

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.

Theophylline (1,3-Dimethylxanthine) is a methyl xanthine derivative from tea with diuretic, smooth muscle relaxant, bronchial dilation, cardiac, and central nervous system stimulant activities. It inhibits the 3', 5'-cyclic nucleotide phosphodiesterase that degrades cyclic AMP, thus potentiating the actions of agents that act through adenylyl cyclases and cyclic AMP.

Isoprenaline hydrochloride (NCI-c55630) is a potent beta-adrenergic agonist with the peripheral vasodilator, bronchodilator, and cardiac stimulating properties.

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.

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