The PGM5P3-AS1 gene, also known as PGM5P3 antisense RNA 1, is a long non-coding RNA (lncRNA) that plays a role in the regulation of gene expression. Below, I provide a detailed overview related to your queries:

### 1. Associated Genes
PGM5P3-AS1 has been associated with several other genes, particularly within the context of certain pathological conditions. Some notable associated genes include:
- **PGM5:** This is the primary associated gene, with PGM5P3-AS1 situated in an antisense orientation to the PGM5 gene.
- **Other lncRNAs:** Genes that may interact or share regulatory networks with various lncRNAs related to cellular stress and inflammation.

### 2. Aging and Age-related Diseases
Research on PGM5P3-AS1 in relation to aging and age-related diseases is limited; however, like many lncRNAs, it may play a role in:
- **Cellular senescence:** Long non-coding RNAs are often implicated in the regulation of cellular aging processes.
- **Cancer:** Certain lncRNAs, including PGM5P3-AS1, may contribute to the tumorigenesis process, which is commonly linked with aging.
- **Metabolic disorders:** Given that lncRNAs can regulate metabolic pathways, it is plausible that PGM5P3-AS1 may interact with metabolic dysregulation related to aging.

### 3. Known Drug or Drug Classes
As of the latest data, specific drugs or drug classes that interact directly with PGM5P3-AS1 are not well-established. However:
- **Targeting lncRNAs therapeutically:** There is potential for the development of drug designs aimed at lncRNAs, including mechanisms to inhibit or enhance their expression, but specific candidates are not yet known for PGM5P3-AS1.
- **Compounds affecting PGM5:** Since PGM5 might have interactions that could reflect on PGM5P3-AS1 (due to proximity and regulatory functions), further investigations are required to elucidate any drug interactions.

### 4. Pathways and Biological Processes
PGM5P3-AS1 is involved in various biological processes, primarily through its regulatory roles:
- **Gene expression regulation:** As a lncRNA, it may modulate transcriptional and post-transcriptional processes of nearby genes, especially in the context of the PGM5 gene.
- **Inflammatory response:** It may be involved in the pathways relevant to the inflammatory response, which is a significant factor in many age-related diseases.
- **Cellular response to stress:** Involvement in cellular mechanisms responding to oxidative stress or other external stresses, common in aging and cancer pathways.

In summary, while PGM5P3-AS1 is recognized within the gene annotation databases primarily as an antisense RNA related to PGM5, its precise functions, implications in aging, associations with drugs, and pathways remain significant areas for further research.